Small betta filter

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What Are the Best Filters for Bettas? - Pin

When it comes to setting up a betta tank, one of the easier decisions is choosing your filtration system. While these fish have some specific preferences when it comes to their water temperature, picking the best filter for bettas is a pretty straightforward proposition.

The key to choosing the right filter is picking one that’s suitable for the size of your betta tank. Beyond that, most systems can be adjusted to provide the gentle circulation that betta’s prefer. Even filters that are not naturally low flow can often be modified at home.

Quick Comparisons of the 5 Best Betta Filters

Quick Guide to Betta Filters

Of all the decisions you face when buying a great tank for your betta fish, the one you shouldn’t stress over is picking out your filtration system.

Why You Might Need a Filter and Benefits

Let’s tackle the most important question first: Do you have to get a filtration system for your betta tank? No. You don’t have to get a filter if you’d prefer not to have one. But having a filter definitely keeps your tank cleaner and reduces the frequency of water changes.

Bettas really like having a clean tank, and a filthy tank causes stress and often leaves you with a dull colored, sick fish. But they are not terribly picky about how their water is cleaned. If you opt against getting a filter you can make it up to your fish by doing regular water changes.

I still recommend getting a filter as long as you can find one that’s quiet, affordable and fits into your betta tank. But unlike having an aquarium heater, a betta filter is an optional piece of equipment.

Aquarium filters have two jobs:

Aquarium equipment. External Aquarium Fish Tank Canister Filter. Vector illustration. The scheme of the external aquarium bio filter. – stock illustration
  • They circulate water around the tank, which helps oxygenate the liquid so your fish don’t suffocate.
  • They “clean” the aquarium water as it circulates.

Betta fish don’t need a high level of oxygen in their water, since they have an organ that allows them to breathe air. They actually don’t like a high rate of water circulation and prefer low flow filters.

Choosing the Ideal Betta Filter

With all this variety at your fingertips, how do you choose the best option for your betta tank? Consider these factors as you shop for filtration systems:

Types of Aquarium Filters

Aqueon LED 7.5 Gallon Shrimp Aquarium Kit

Aquarium filters come in all sizes and shapes, but the most common options for betta tanks are usually small and inexpensive. Some aquariums are even designed with built-in filtration systems, so you don’t have to add one later.

If your tank doesn’t have a filter, these are some styles available for tropical fish tanks and suitable for bettas:

  • Sponge filter with an external air pump.
  • Filter with stages that hangs off the back of your tank (HOB filter).
  • Undergravel filter with carbon cartridge and external air pump.
  • Submersible or internal flow filter.

For a small betta tank, any of these options work really well, so pick the one that suits your tank the best. Some filters just have a nicer appearance than others, so if that’s an important factor for you, pick the style that you think looks best!

While each type of filter has advantages and disadvantages, the differences in performance for a small tank are pretty minimal. It’s hard to discuss filters just by breaking down the different styles, because within each type you’ll have a wide variety of sizes, features and options.

Pick the Right-Sized Filter for Your Betta Tank

Aqueon Quietflow Internal Power Filter inside aquarium tank.

You obviously want to pick a filter that physically fits inside or on your tank and leaves plenty of room for your decor and betta. The easiest way to identify a good option for your tank is to look at the size rating on the filter in question. Nearly all of these products will say which sizes of tanks their filter is designed for.

It’s best to avoid buying a more powerful filter than you need for your tank.

If the filter has a wide range, say 5 to 20 gallons, it might not be the best option for your 5-gallon betta aquarium. Go with a filter designed for a 5-gallon instead of one with a broad range. Definitely get a filter with an adjustable or low flow if you can.

How Many Stages Do Betta Filters Need?

There are three ways a filter can function to keep your aquarium water clean. Think of these as stages. Some filters have multiple stages and clean your water in two or three ways, while others use a single stage.

Filter Stages Chart

The most important stage for a betta filter to have is the first one—a filter pad for debris removal. Removing debris, which may include fish waste, old food or plant material, prevents them from rotting in your tank and fouling your water. But you still have to regularly clean and/or replace the pad in your filter.

I’d prioritize getting a betta filter with the first two stages, if possible: Filter media helps keep your water clear and smelling fresh. Depending on the type of media in your filter, they may remove chlorine, chloramine, copper, ammonia and aquarium medications from the tank water.

Noise Level of Filter and Pumps

It’s amazing how noisy an aquarium can be, and filters are probably the worst offenders. It’s not actually the filter that makes the most noise; it’s the pump that really turns up the volume.

Close up shot of AquaClear - Fish Tank Filter.
  • HOB-style and built-in filters have an integrated electrical pump that moves the water around. These are usually the quietest styles.
  • Sponge and the submersible types of filters are hooked into a separate air pump via a line of thin plastic tubing.These suckers can be noise bombs!

It’s not just that the pump makes a lot of noise itself. A high quality air pump is usually pretty quiet. But their vibration can be super annoying if they touch the side of a table or aquarium stand. Placement is key to minimizing the vibration and noise.

  • If your betta tank is located in a bedroom or other area where you need to keep things quiet, you might want to avoid filters with these external air pumps.
  • Opt for a HOB, submersible or a tank with a built-in filter instead.

Maintaining Your Filter—Can You Find Replacement Parts?

An aquarium filtration system may save you time by reducing the frequency of water changes, but they still have to be cleaned and maintained. A filter that’s designed to be accessible and easy to clean will make this chore a lot less annoying.

Lefunpets Biochemical Sponge Filter Breeding Fry Betta Shrimp Nano Fish Tank for Aquarium Fish Tank 5 Gal-25 Gal spare parts
  • Typically, you’ll need to clean your filtration system and replace the filter pad and/or media at least once a month.
  • It’s easiest to do this filter maintenance along with your water changes.

Filter pads and media cartridges can restrict the water movement if they get clogged.

  • This can increase the noise your filter makes and may even burn out your filter’s motor. You should check your filter every week or at least every other week to avoid problems.

It’s always a good idea to check the availability and cost of commonly-replaced parts to your filter before you plunk down your money. Can you easily and affordably find replacement filter pads, cartridges and media?

Using a Baffle to Modify Your Betta Tank Filter

Close-up betta filter baffle

A baffle is a fancy term for something you place over the outflow of your filter to reduce the water current. Many filters have an adjustable flow rate, but sometimes that’s just not enough in a small betta tank.

A baffle can be something as simple as a cheap, disposable plastic cup or bottle. Cut it into the size you need and use it to redirect the flow of water as it comes back into your tank. It’s hard to give more concrete instructions because it depends on your filter and aquarium set-up.

You may not need a baffle, but you’ll likely know it if you do. Your betta will avoid the areas of choppy water. If you turn your filter off and suddenly your betta is happy and swimming all over your tank, you probably need to add a baffle to your filter’s outflow.

Top 5 Betta Filter Reviews

Let’s take a look at some filtration systems and set-ups that are ideal for a betta tank. I’ve tried to find options to suit a wide variety of aquariums, including betta bowls and small tanks.

I don’t usually recommend keeping bettas in aquariums under 5-gallons. If you have a filter, do weekly water changes and pay diligent attention to your betta’s color and appetite, a small tank can work. Even if it isn’t ideal. You’ll likely have to modify your filter with a baffle, however.

1. Aqueon 7.5 Gallon Aquarium Kit

Aqueon LED 7.5 Gallon Shrimp Aquarium Kit
  • Type of Filter: All-in-One (Built into aquarium)
  • Stages: Mechanical and Chemical; 2-Stage filter
  • Size: 14.5 x 14.5 x 13.5 inches
  • Power: Electrical
  • Suitable For: Raising Fry, Adults and Breeding Tanks
  • Tank Size: 7.5-gallons

One of the easiest ways to set up a filtration system is to buy a tank that includes one! It can be a bit more expensive up-front to get an all-in-one betta tank, but it saves you the hassle of deciding on a filter style and figuring the best way to place it in or on your tank.

The Aqueon 7.5-gallon aquarium kit comes complete with the basic supplies you need to set up your betta tank. It has a gentle 2-stage filter with a filter pad and a replaceable carbon cartridge. What I love about this setup is how easy the filter is to access. 

You can check the filtration system from the top of your tank by lifting the lid—it’s so simple! This set-up is an ideal option for a betta, and the filter is gentle enough for raising fry and shrimp too. At 7.5-gallons, it’s got plenty of room for an adult fish and decor, and there’s no reason you couldn’t grow live plants in this tank as well.


  • Complete aquarium set-up includes everything you need to start a betta tank.
  • 2-stage filter removes debris and cleans the water, reducing the frequency of water changes.
  • Filter is built into the hood and easy to access.


  • May be more expensive to purchase a complete set-up.
  • Since filter is built into the hood, the noise level may increase as the water evaporates.
  • Filter can’t be reused separately for other tanks since it is integrated into the aquarium.

2. Upettools Single Head Bio-Sponge

UPETTOOLS Aquarium Biochemical Sponge Filter in white background
  • Type of Filter: Sponge Filter
  • Stages: Mechanical and biological; 2-stage
  • Size: 2.76 x 2.76 x 7.48 inches
  • Power: Requires air pump and tubing
  • Suitable For: Raising Fry, Adults, Breeding and Hospital Set-ups
  • Tank Size: 2 to 40 gallon
Check The Price

Every aquarist should keep a sponge filter like this in their arsenal of aquarium equipment

Sponge filters are ideal for tank’s of all types, and are especially useful for breeding set-ups, raising fry and hospital tanks. They’re also ideal for betta tanks, since they’re gentle, have a low flow rate and rarely produce much current. This single-head filter from Upettools is just about the most impressive sponge filter I’ve ever seen, and has a couple of unique features worth checking out!

Sponge filters are typically simple set-ups that provide mostly mechanical filtration  and help circulate the water around your aquarium. They’re powered by an external air pump and connect to the filter with plastic tubing (sold separately). Dirty water is drawn through the fine sponge tip, where debris collects until you can rinse them away. They also provide a bit of biological filtration, since the “good aquarium” bacteria living in the sponge helps break down waste. But sponge filters can’t usually provide robust bio-filtration or any chemical filtration at all.

The Upettools bio-sponge, on the other hand, gives you the option of adding chemical media or long-lasting bio media to your tank as well! It has a small compartment under the sponge tip that you can customize with the media of your choice, and you can leave the media out if you’re using medications or treating a sick tank. This filter is adjustable, so it’ll fit in any part of your tank, and the outtake tube even extends from 7 to 11-inches high for bigger aquariums. The unique sponge tip has a ribbed design and can trap more debris than most, too. I highly recommend this filter!


  • Inexpensive filter that’s easy to adjust for set-ups from 2 to 40 gallons, including betta bowls.
  • Media canister can be used for additional biological filter media, or you can use carbon or ammonia chips and turn it into a 3-stage filter!
  • Provides the ideal gentle flow rate betta fish prefer, and suitable for  breeding, raising fry and hospital tanks.


  • Amount of media it can hold is limited, so you may need to change it more frequently than a larger HOB or internal filter.
  • Sponge tip requires weekly maintenance to prevent the filter from clogging.
  • Also needs an air pump to operate (sold separately), which may produce too much noise for a betta tank in a bedroom.

3. AquaClear 20

AquaClear - Fish Tank Filter
  • Type of Filter: HOB
  • Stages: Mechanical, Chemical and Biological; 3-Stage filter
  • Size: 4.5 x 7 x 6.5 inches
  • Power: Electrical
  • Suitable For: Adult Bettas
  • Tank Size: 10 to 20 gallon tanks

The AquaClear 20 is an impressive and inexpensive 3-stage HOB filter for tanks from 10 to 20-gallons in size. It comes with a filter sponge pad, replaceable carbon cartridge and large basket for holding biological or other media. The flow rate is adjustable with the touch of a knob.

It’s pretty quiet once you have it installed, although the vibration is noticeable when the lid is left loose. It’s very easy to access the padding and media for maintenance, and the clear plastic housing lets you see what’s going on inside the filter.

The AquaClear is a good option for larger betta tanks but may need to be modified for smaller ones. Personally, I’d cover the filter intake (the part that draws water from the aquarium into the filter) with some filter padding or a sponge filter, to prevent your betta from being sucked into the filtration system.


  • Filter fits most standard-sized 10 and 20-gallon tanks, and can be swapped from tank-to-tank easily.
  • 3-stage design and included media provide mechanical, chemical and biological filtration, reducing the frequency of water changes.
  • Provides the ideal gently flow rate betta fish prefer.


  • Hard plastic case may rattle or vibrate if lid or other parts are placed loosely.
  • The water flowing into the tank from the outflow may be noisy as the water level drops.
  • Does not come with a sponge filter for the intake, so you may need to purchase this separately.

4. Aqueon Quietflow

Aqueon Quietflow Internal Power Filter
  • Type of Filter: Submersible/Internal Flow
  • Stages: Mechanical, Chemical and Biological; 3-Stage filter
  • Size: 2.8 x 1.5 x 5.4 inches
  • Power: Electrical
  • Suitable For: Adult Bettas
  • Tank Size: 10-gallon tank
View on Amazon

If you’d prefer a filtration system that is very quiet and discrete, then this submersible filter might be the best option for your 10-gallon betta tank. The Aqueon Quietflow 3-stage internal power filter sits inside of your aquarium, where it works without having to pump the water out of your tank.

This means it provides the same level of filtration as built-in or HOB-styles, but doesn’t need to use as much power. It works in any orientation, and can be attached to your tank’s side with suction cups. The filter has an adjustable flow rate, and the outtake swivels so you can direct the current as you wish.

The Aqueon could be a great option for a betta tank in a bedroom or other location where the filter’s noise might be a concern. Since it goes inside the aquarium, the low-powered filter’s sound is barely detectable when it’s on, and there’s no noise from the water outtake.


  • Submersible 3-stage filter fits in any shaped-aquarium of suitable size.
  • One of the quietest filter styles, so it’s ideal for bedrooms.
  • Provides a gently flow rate and rarely needs to be baffled for bettas.


  • Filter must be removed from the tank for maintenance.
  • You may have to modify your aquarium hood to accommodate the power cord.
  • Filter is a bit large to fit in smaller betta tanks under 10-gallons in size.

5. Azoo Mignon

AZOO Mignon Filter 60
  • Type of Filter: HOB
  • Stages: Mechanical and Chemical; 2-Stage filter
  • Size: 3.2 x 3.8 x 6 inches
  • Power: Electrical
  • Suitable For: Adult Bettas
  • Tank Size: 2.5-gallon betta bowl to 5 gallon tank
Check The Price

Finding a good filter for a betta bowl or nano tank, as they’re often called, can be a challenge, especially if you want a HOB-style filter for your aquarium. The Azoo Mignon is an HOB nano filter with a clear plastic housing. It has an adjustable flow rate that’s very easy to use.

The Azoo offers 2-stages of filtration and includes a filter pad and replaceable carbon cartridge. It also comes with a sponge filter for the intake, so your betta won’t get injured by accidently getting pulled into the filtration system. I especially like that the Azoo comes with a sponge filter for the intake.

While this filter says it’s designed for 3.5-gallon aquariums, it’s actually ideal for betta tanks from 2.5 to 5-gallons. This might actually be the best filter for a 2.5 gallon betta tank or bowl on my list, if it fits and you baffle the outflow. While it may technically be underpowered for a 5-gallon, that makes it perfect for raising a betta fish!


  • Inexpensive nano HOB ideal for betta tanks from 2.5 to 5 gallons.
  • 2-stage replaceable filter offers both mechanical and chemical filtration.
  • Comes with a sponge filter to cover the intake, protecting your betta from injury.


  • Design may not fit in curved tanks or round betta bowls.
  • Sponge filter on the intake requires weekly cleaning to prevent debris from clogging the system.
  • Noise may be noticeable if water level drops below the top of your tank.


Close up of Aqueon Quietflow Internal Power Filter in the aquarium.

As you can see, choosing a filter for betta tanks is not a difficult decision. It mostly comes down to which style you prefer and which one best fits into your tank. Modifying your aquarium filter with a baffle, or sponge filter over the intake tube, is usually an easy and affordable way to make nearly any filter work with your tank.

If you’re still not sure which style of filter you should get for your aquarium, consider this last bit of advice:

  • If you have a tank that’s 10-gallon or larger, consider the Best HOB Filter, the Aqua Clear. You may need to modify it for your set-up, but it’s a great all-around option for most bigger betta tanks.
  • If noise is a concern, the Best Submersible Filter, the Aqueon Quietflow, is an excellent option and priced very reasonably. It’s so quiet you might forget you even have a filtration system in your tank.
  • If you need a small filter for your betta bowl or tank, consider going with the Azoo Mignon, rated as the Best Filter for Nano Tanks. It’s a good choice for tanks from 2.5 to 5-gallons, and I love that it comes with a sponge filter for the intake.
  • It’s never a bad idea to have the Best Sponge Filter set-up available if you need to set up a hospital or quarantine tank. It also makes a great option for betta tanks of all sizes. Since it’s a 1-stage filter, you’ll still have to do weekly maintenance and water changes, but your betta will likely love it.

Hopefully, my quick guide to betta filters has been informative and helpful to you as you plan your tank. I’d love to hear your thoughts in the comments, or tell us about the filtration system you use in your betta tank!

Jen Clifford

Jen has more than 30 years experience as a biologist, aquarist, and fishkeeper. She is an expert in setting up new tanks and maintaining naturally-planted freshwater habitats, and has experience raising a wide variety of aquatic species.


Do Betta Fish Need A Filter?

Whether betta fish need a filter or not depends on several factors including tank size, the level of care, tank mates, and more. It’s not a simple yes or no answer because they can survive and even thrive in both scenarios with the right care.

Problems arise from misinformation and from beginner caretakers who believe a bowl or other small tank is going to be less work and less expensive. That’s simply not true and can lead to a sick betta or worse. Before you make your decision on filtration, make sure you fully read and understand the pros and cons of each.

Let’s start by understanding a betta’s natural habitat, living in rice paddies and shallow bodies of water. During droughts, a wild betta may even end up in a murky puddle for a period of time with very little oxygen. Betta fish are able to survive in these conditions through evolution, with the unique ability to gulp oxygen from the air (at the water’s surface) instead of relying solely on their gills. This ability comes from their labyrinth organ, classifying them as Anabantoidei or labyrinth fish.

Because of their level of tolerance in low oxygenated water, bettas are frequently sought after and recommended for beginners. They can be easier to care for than other tropical fish with less equipment, but myths are abundant. Claims how they prefer small habitats and can live off the roots of a plant in a vase. These claims are false and can lead to your betta merely surviving. Instead, you want your betta to live a long and healthy life without any suffering right?

Betta Fish Without A Filter

Betta Fish Habitats Without Filters

Tanks that are 2.5 gallons or smaller, shouldn’t have a filter because they can do more harm than good. Filters in small tanks cause strong currents, which can toss a betta fish around and stress them out. Bettas are not very strong swimmers and their long fins can further complicate mobility in strong currents. Betta’s prefer slow moving or still water. This is why some caretakers swear by unfiltered tanks for their betta, replicating their natural ecosystem.

Water quality, however, quickly declines in low volume unfiltered tanks. The larger the volume, the slower the water quality will decline and the easier it is to maintain. Uneaten food and feces lead to ammonia, nitrate, and nitrites building up. In high quantities, these can begin to stress and make your betta sick. One of the most common ailments in small unfiltered tanks is fin and tail rot. There are also beneficial bacteria that naturally exist in the water. Constant water changes can limit these beneficial microorganisms and create stress as well.

The absolute minimum size for a betta fish is 2.5 gallons, with the recommended size being 5 gallons or more. Caring for a betta fish without a filter is actually a lot more work. Non-filtered tanks require 1-2 water cycles at around 25% and a full 100% water change each week (depending on water quality). On the other hand, a 5-gallon unfiltered tank will only need 1 water cycle per week at around 25%-35% of total volume and a 100% water change once per month.

You should also use test strips to analyze your water parameters in real-time. To help with unfiltered tanks, remove uneaten food and poop before it settles and decays (pro tip: use an aquarium designated turkey baster to easily suck debris out of the tank). After reading the section below, you’ll quickly realize why filtered tanks can be more beneficial for betta fish and easier to maintain.

Betta Fish With Filtered Tank

Betta Fish Habitats With Filtered Tanks

There are many filters you can buy if your tank did not come with one. Some examples of different types include: under gravel filters, hanging on the back power filters, sponge filters, and internal filters. The most important consideration for betta fish is their strength, with having an adjustable flow being crucial. Your betta should be able to swim freely without struggling.

We recommend purchasing a tank that’s recommended for betta fish and comes with a filtration unit out of the box. Mix-matching items can be tricky, but if you are buying a filter, a weaker than the recommended size is advisable. For example, if your tank is 5 gallons, consider a filter rated for 1-3 gallons.

Benefits of Betta Tanks with Filters

  • Waste Reduction – removal of excess food, feces, ammonia, and bad bacteria
  • Oxygenation – filters help to oxygenate the water
  • Good Bacteria – beneficial microorganisms accumulate in filter media and tanks
  • Tank Mates – filters are required with tank mates because of increased bio loads
  • Maintenance – reduced maintenance and water cycling


Betta fish like filtered tanks because they do best in stable water parameters. A filter helps to maintain beneficial bacteria while cleaning and neutralizing ammonia and nitrates. Establishing a natural ecosystem is crucial to long-term health and limiting the chances of stress and disease.

Filtered betta tanks will require less maintenance, which makes your life easier. If you forget to perform water changes in an unfiltered tank, things can get bad quickly. In a filtered tank you don’t need to do 100% water changes unless you have an algae or rampant disease problem. In fact, a 25-30% water cycle once a week and vacuuming the gravel is all that’s necessary aside from filter media replacement per your filter’s instructions. Make sure to always clean your filter in tank water and not tap water to preserve beneficial bacteria.

Is Your Bettas Filter Too Strong?

If your betta’s filter is too strong you will need to remove it or reduce the strength of the current. Filters are not ideal for tanks under 3 gallons and you should upgrade the size of your betta’s habitat. Hanging on the back and internal filters come in varying strengths and may be too strong for a betta fish. If your betta is struggling to get to the surface for air, hiding and scared, and frantically swimming in the current, your filter is probably too strong.

This can severely stress your betta fish and lead to fin damage, injuries, and even death. After becoming physically exhausted they can be tossed around or even sucked up by the filters intake tube. Allowing your tank’s water to get and stay below the recommended depth from the filter’s output will also increase turbulence in the water.

The first thing to try is limiting the flow of your filter if it’s adjustable (try the lowest setting). If not, consider returning it, purchasing a new one, or trying these tips. You can increase plants and decorations near the filter to break the flow as it enters the tank. There are also other methods like creating a separate compartment for filtration by dividing the tank.

Another quick fix which will also protect your betta fish is placing a pre-filter sponge on the intake tube to restrict water uptake and ultimately output. Pre-filter sponges will easily fit over certain filters’ output tubes into the aquarium like the Fluval Spec V too. This can help to reduce the flow and turbulence in the tank for betta fish.

Filters For Betta Fish

Recommended Betta Filters

The size of your tank or habitat will affect which filter is right for your betta. One of the best and most inexpensive options for smaller tanks are sponge filters (on the left). Sponge filters use bubbles of air from an air pump to draw water through a sponge. A sponge filter is very easy to set up and allows for both mechanical and biological filtration. They are perfect for the delicate betta, and also have the added benefit of oxygenation. They work best in tanks up to 10 gallons and present virtually no risk to your betta from suction or flow.

A second option is the hanging on the back (HOB) nano filter (middle). These are ideal for 5-10 gallon or even larger tanks. If you can, get one that has an adjustable flow rate and consider a pre-filter sponge for the intake tube. HOB filters are easy to maintain and they don’t take up viewing or ecosystem space.

A final option is an internal filtration unit that goes inside the tank (on the right). If you already have a small tank (3 gallons), this can reduce swimming space and the overall water volume available for your betta fish. Most submersible filters attach to the tank’s wall via suction cups and perform relatively well if they’re not too powerful.


Do betta fish need a filter? That depends on what you’ve decided given the pros and cons for each scenario above and your personal situation and preference. Please avoid fish bowls and any tank under 2.5 gallons. The larger your tank, the easier it will be to maintain. A filtered tank can further support a healthy ecosystem too. If you decide to introduce tank mates, create a sorority, or place your betta fish in a community tank, filtration will be required for increased oxygenation and water quality.

If you still have questions, please ask them in the comments below.

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Looking for the best filter for your betta fish tank? In this guide, you’ll be walked through how to select the filter that’s best for your setup.

You’ll learn how to choose one, the different options available and my favorite products for each category.

By the end, you’ll know exactly what you need.

Table of Contents

Product Table for Betta Fish Filters


Lee’s 40/55 Premium Undergravel Filter

Jardin Aquarium Corner Filter

Filter Type

HOB (Hang on Back) Filter



Fluval 206 External Filter

Filter Type



XY-2831 Air Pump Sponge Filter for Aquarium, Tank Size 10-Gallon (1-Pack)

Filter Type


AquaClear, Fish Tank Filter, 5 to 20 Gallons, 110v, A595


Filter Type

HOB (Hang on Back) Filter


Lee's 40/55 Premium Undergravel Filter, 12-Inch by 48-Inch


Lee’s 40/55 Premium Undergravel Filter

Filter Type


Jardin Aquarium Efficient Economy Corner in Tank Filters


Jardin Aquarium Corner Filter

Filter Type


Koller Products TOM Aquarium Internal Power Filter (45 GPH Flow Rate)


Filter Type

Last update on 2021-10-01 / Commissions Earned / Images from Amazon Product Advertising API

Do Betta Fish Need a Filter?

The short answer is yes, betta fish do need a filter.

Betta fish need clean water to live well in their tank, just like any other fish you might keep. Poor water conditions can lead your betta fish to succumb to disease or to suffer from issues like fin deterioration.

A filter goes a long way towards preventing the buildup of harmful microorganisms and organic detritus from uneaten food and fish waste. Cycling the water in the tank through the filter also helps to oxygenate the water, which can lead to overall healthier conditions in the tank for your betta.

Just as important, a filter drastically reduces the amount of work you need to do to keep the tank clean – which means you’re more likely to keep up with tank maintenance. For tanks with a filter, you only need to replace about 30% of the water and vacuum the gravel each week.

All of that takes just a few minutes of work compared to a betta tank without a filter. While a tank without a filter can work, you need to change out all the water each week and thoroughly clean all of the decorations in the tank.

That means a lot of distilled water, a lot of cleaning time, and a lot of stress for your betta as you transfer it to a holding tank while you clean out the aquarium.

For all these reasons, it’s well worth investing in a filter for your betta fish.

There are a number of different types of filters available, all of them with different characteristics.

So what filter features matter for your betta fish? Here, we’ll highlight the most important things to watch out for when choosing a filter.

Flow Power

Betta fish do best with a filter that has a low flow power. Otherwise, they tend to get knocked around by the currents created by a high-powered filter – and that can cause stress.

Ways to Reduce Flow If Your Filter is Too Powerful

If you find out that your filter is too powerful for your betta fish, there are some things you can try to reduce the flow.

First, if you have an adjustable filter, you can simply adjust the flow rate. This is the simplest solution, but you’ll still be limited by the minimum flow rate on your filtration system.

If adjusting the flow on the filter isn’t an option, you can limit the water intake. The best thing to use for this is a pair of pantyhose, which can be cut to fit over the filter intake and slow down the rate of water entering the filter.

Short of cutting the flow, you can disperse it with a baffle. A baffle is anything that works to block and slow down the water from the filter outlet.

Common baffles include mesh tank screens and inexpensive kitchen sponge holders that can be suction-cupped to the side of the tank.

Finally, you can help your betta hide from any excessive flow coming from your filter by placing decorative plants, logs, and other items throughout the tank.

These decorations effectively give your betta plenty of places to rest without having to worry about the water current from the filter.

How Big is Your Betta’s Tank?

The flow rate you need in a filter also depends on the size of your betta tank.

Your filter should cycle through all of the water in the tank four times per hour. So, to figure out the minimum flow rate you need, in gallons per hour, multiply the size of your tank in gallons by four.

However, remember that this number is just a base calculation that indicates the flow rate needed when there is nothing in the tank. If your betta tank is filled with decorations, you will need a slightly more powerful filter than that calculation suggests.

Finally, keep in mind that using multiple smaller filters is better than opting for one large filter. Using multiple filters will minimize the current that your betta has to fight against and improve the overall filtration of the tank.

Filtration Stages

There are three stages to filtration in an aquarium: mechanical, biological, and chemical.


Mechanical filtration is the first step of filtration, in which any particles floating in the water are removed. Ceramic cylinders, coarse sponges, and filter floss are all common media for mechanical filtration.


The biological stage of filtration incorporates beneficial bacteria that remove organic matter – like uneaten food and fish waste – from the tank water.

The biological filtration portion of the filter typically includes media that is friendly for bacteria to grow on, such as Bio-balls or porous ceramic cartridges.


Chemical filtration is designed to re-balance the chemistry of the water and to remove any chemical impurities that are dissolved in the water. The most common chemical filter medium is carbon, since it has a short one-month life.

7 More Tips on Choosing Your Betta Fish Filter

1. Keep the output current low or disperse the outflow from the filter as much as possible. This will reduce the amount of fighting against the current that your betta will need to do.

2. Look for a filter with a cartridge system that makes it easy to remove and replace any of the mechanical, biological, or chemical stages of the filter. This makes maintaining the filter much simpler and faster, and allows you to change out just the part of the filter that needs replacing.

3. Make sure that the filter you choose has the flow rate and mechanical, biological, and chemical filtration stages needed to keep your aquarium clean.

Remember that the flow rate you need may be higher depending on how much stuff is in your tank. In addition, some natural decorations like driftwood can leach impurities into the water that may require special chemical filtration.

4. Consider the filter media – does it have mechanical, biological, and chemical media, or just two of the three? What media you need depends on what else is living in your tank besides your betta, so we’ll cover this more below.

5. Think about reliability. You need a filter that is likely to work over the long-run without clogging or breaking down frequently. Taking other people’s experience with a specific filter into account can go a long way towards saving you from dealing with a poorly made filter.

6. Look for a filter with an adjustable output. Having the ability to adjust your filter’s output makes it much easier to lower the flow rate if your betta is stressed by the current in the tank.

7. Consider whether a filter matches your tank’s aesthetics. While any filter still needs to be practical in all other regards, it doesn’t hurt to have it blend in with your tank decoration.

Popular Types of Filters Available for Betta Fish Reviewed

Now that you know what to look for in a filter for your betta fish tank, let’s look at some of the most popular types of filters for betta fish. We’ll also highlight our favorite model of each type of filter.

1. Canister Filters

Canister filters are a high-throughput filtration option for betta tanks of nearly any size.

This type of filter actually pumps water out of the tank, through a pressurized canister, and back to the tank via a spillway or spray bar.

This allows canister filters to boast high water flow rates. They also don’t distract from the aesthetic of the tank since they are hidden behind or underneath the aquarium and are very quiet.

The most important advantage to canister filters is that you can customize the media that is inside them to suit your tank’s needs. They are also easy to open up for cleaning and replacing media.

However, the high flow rates of canister filters aren’t always a good thing for betta fish, especially since the outflow is pressurized. Especially in smaller tanks, this pressurized flow can create stressful currents for your fish.

Best Canister Filter for Your Betta Reviewed: Fluval External Filter 206

This canister filter is designed to handle tanks up to 45 gallons in volume and features all three of mechanical, biological, and chemical filtration stages.

Fluval sells a wide range of media so you can customize the filtration process to match your betta’s needs as closely as possible. Plus, the chemical and biological stages use separate media so they can be changed out independently of one another.

The canister is designed with a sound-dampening impeller so you’ll barely know it’s there when you’re not changing out the media. Plus, the intake strainer and dual layer foam screen are designed to drastically reduce the incidence of clogs.

While the outflow is somewhat powerful for a betta fish and will likely require you to install a baffle, the pressurized flow also does an excellent job of aerating your aquarium.

Fluval 206 External Filter
Fluval 206 External Filter

Last update on 2021-10-01 / Commissions Earned / Images from Amazon Product Advertising API

2. Sponge Filters

Sponge filters function by sucking water through a porous sponge material, which serves to provide both mechanical and biological filtration. The biological filtration is highly effective because helpful bacteria are able to colonize the porous spaces of the sponge.

One of the major advantages to sponge filters for a betta tank is that the suction through the filter is created by an air stone rather than a pressurized pump. That leads to relatively gentle water outflows, which are ideal for betta fish.

In addition, sponge filters tend to be one of the least expensive filtration options and don’t require much maintenance.

The main downside to sponge filters is that they are large and not aesthetically pleasing. Most people who use sponge filters opt to hide them behind decorative kelp, in the rear of the tank.

In addition, sponge filters do not provide chemical filtration. However, it is possible to add a carbon filter to the outflow of a sponge filter if needed.

Best Sponge Filter for Your Betta Reviewed: Xinyou XY-2831 Sponge Filter

This inexpensive sponge filter from Xinyou is designed to provide mechanical and biological filtration for a tank that is 10-20 gallons in size.

While the filter does not come with an air stone, it is easy to outfit with a small stone to create a highly efficient suction system that won’t stress out your betta fish.

The filter is extremely simple in design and can be used as a pre-filter or as a standalone filter. The sponge material works well as a home for beneficial bacteria, as evidenced by the attraction of shrimp towards this filtration device.

The only real downside to this filter is that it is not pretty – the black, mechanical-looking design is certain to be out of place with any tank aesthetic, so you’ll want to hide it behind some other decorations.

XY-2831 Air Pump Sponge Filter for Aquarium, Tank Size 10-Gallon (1-Pack)
XY-2831 Air Pump Sponge Filter for Aquarium, Tank Size 10-Gallon (1-Pack)

Last update on 2021-10-01 / Commissions Earned / Images from Amazon Product Advertising API

3. HOB Filters

HOB – hang-on-back – filters are designed to suck water out of the aquarium and through a filter that offers mechanical, biological, and chemical filtration.

Since they are behind the tank, HOB filters are easy to access for maintaining the media and don’t detract from your tank’s available space or aesthetic.

HOB filters typically offer more effective mechanical filtration than sponge filters. However, many aquarists recommend using a sponge filter as a pre-filter to HOB filters since they offer better biological filtration.

Using a sponge pre-filter also protects your betta fish from the relatively strong inflow rates of HOB filters.

In addition, HOB filters often have outflow rates that can be distressing to betta fish. Thus, when choosing a HOB filter, it is important to look for one that has an adjustable flow rate.

Best HOB Filter for Your Betta Reviewed: AquaClear Power Filter

This HOB filter from AquaClear offers a number of advantages for betta fish, the most important of which is a re-filtration system that allows you to control the outflow rate.

At slower flow rates, up to half the water in the filter is processed multiple times, which also gives this filter some of the most impressive water contact times of any filter on the market.

The filter comes with AquaClear foam as a mechanical filtration media, activated carbon for chemical filtration, and BioMax and Cycle Guard for biological filtration.

The relatively large size of the filter allows it to contain large volumes of media, and the media is straightforward to customize to better meet your betta’s needs.

While this model is designed for tanks up to 20 gallons, AquaClear offers the same HOB filter in multiple sizes to fit tanks of any volume.

AquaClear, Fish Tank Filter, 5 to 20 Gallons, 110v, A595
AquaClear, Fish Tank Filter, 5 to 20 Gallons, 110v, A595

Last update on 2021-10-01 / Commissions Earned / Images from Amazon Product Advertising API

4. Undergravel Filters

An undergravel filter is a set of plates that sits underneath the gravel media at the bottom of your aquarium and sucks water through the gravel before recirculating it to the top of the tank.

This type of filter provides effective mechanical and biological filtration as water travels through the gravel, and some models provide chemical filtration modules in the outflow tubing.

Importantly, since this type of filter traps debris inside the gravel within the tank, it is extremely important to use a gravel vacuum on your tank frequently to keep the tank clean and maintain the chemistry of the water.

In addition, while undergravel filters distribute the water inflow across the base of the tank, reducing currents in that direction, the outflow can be quite strong. Depending on the design of the filter, this may be a problem for your betta or the water may be directed all the way to the water’s surface.

Best Undergravel Filter for Your Betta Reviewed: Lee’s 40/55 Premium Undergravel Filter

This inexpensive undergravel filter from Lee’s is an ideal choice for betta fish because it uses a single plate that distributes the inflow current across the entire base of the tank.

In addition, the siphons are designed to output water all the way to the tank’s surface so that the impact of the outflow current on your betta fish is as minimal as possible.

In addition to filtering water through the gravel, this undergravel filter includes activated carbon add-ons that can be attached to the outflow tubing.

Another advantage to this filter is that the plastic bedding itself is quite durable compared to other undergravel filters. As a result, you won’t need to remove the filter from your tank during the life of your betta fish.

Lee's 40/55 Premium Undergravel Filter, 12-Inch by 48-Inch
Lee's 40/55 Premium Undergravel Filter, 12-Inch by 48-Inch

Last update on 2021-10-01 / Commissions Earned / Images from Amazon Product Advertising API

5. Corner Filters

Corner filters are one of the oldest, tried-and-true types of filters out there. These filters are designed for tanks up to 25 gallons in size and typically sit in the rear corner of the tank.

They function by using an air stone to push water through the filter, which contains a variety of media to mediate mechanical, biological, and chemical filtration.

There are several advantages to corner filters. First, they can be filled with a custom media mix to perfectly match the needs of your betta fish.

Second, they use an air stone to bubble water through the filter, which does not create much current that could disturb your betta fish. Finally, corner filters are one of the least expensive filtration options available.

The only downside to corner filters is that they can make it more difficult and time-consuming to change out the media than canister or HOB filters.

Best Corner Filter for Your Betta Reviewed: Jardin Aquarium Corner Filter

This small corner filter from Jardin is ideal for small betta tanks that are too heavily disturbed by other types of filters. The filter is as simple as it gets, with just a single chamber that can be opened from the top to allow you to add in custom filtration media.

The outflow tubing can be pulled apart to augment how water is outflowed – whether straight up or across the back of the tank. With a small air stone, this filter will not cause excessive currents even in a small 5-10-gallon betta tank.

Jardin Aquarium Efficient Economy Corner in Tank Filters
Jardin Aquarium Efficient Economy Corner in Tank Filters

Last update on 2021-10-01 / Commissions Earned / Images from Amazon Product Advertising API

6. Internal Power Filters

Internal power filters are designed to sit inside your tank and flow water through a variety of filtration media types. The primary advantage to internal power filters is that the outflow can often be turned in any direction and adjusted using an internal flow meter.

The main downside to internal power filters is that unlike other filter types, you will not have as much control over the composition of the filtration media.

While that may not be an issue for tanks that are typically clean with just any filtration, for aquariums that have issues with water chemistry or disease outbreaks you may want more customization of your filtration system.

Best Internal Power Filter for Your Betta Reviewed: Koller Products TOM

This small and versatile filter from Koller Products is designed specifically for small betta tanks less than 10 gallons in volume.

The outflow is distributed across a set of 10 nozzles to reduce the current that your betta fish feels, and the filter can be pointed in any direction within the tank to further minimize its impact on your fish.

Even better, the flow rate of the filter can be easily adjusted to account for the size of your tank.

The filtration media inside the tank is dense foam with activated carbon, which provides a measure of all three stages of filtration.

While the media volume is relatively small, this is not an issue for small tanks and the media does not need to be replaced more than once every several months.

Koller Products TOM Aquarium Internal Power Filter (45 GPH Flow Rate)
Koller Products TOM Aquarium Internal Power Filter (45 GPH Flow Rate)

Last update on 2021-10-01 / Commissions Earned / Images from Amazon Product Advertising API

Alternative: Aqueon Quietflow E Internal Power Filter
Alternative: Aqueon Quietflow E Internal Power Filter

Last update on 2021-10-01 / Commissions Earned / Images from Amazon Product Advertising API

Which Filter is Best for Your Betta?

Which filter is best for your betta depends on a number of factors, including the size of your tank, which filtration stages you need, and your budget.

The most important things when choosing a filtration system are that it has the right media to keep your water clean of harmful bacteria and debris that could alter the water chemistry, and that the filter itself does not create a current that could stress out your betta fish.


Lee’s 40/55 Premium Undergravel Filter

Jardin Aquarium Corner Filter

Filter Type

HOB (Hang on Back) Filter



Fluval 206 External Filter

Filter Type



XY-2831 Air Pump Sponge Filter for Aquarium, Tank Size 10-Gallon (1-Pack)

Filter Type


AquaClear, Fish Tank Filter, 5 to 20 Gallons, 110v, A595


Filter Type

HOB (Hang on Back) Filter


Lee's 40/55 Premium Undergravel Filter, 12-Inch by 48-Inch


Lee’s 40/55 Premium Undergravel Filter

Filter Type


Jardin Aquarium Efficient Economy Corner in Tank Filters


Jardin Aquarium Corner Filter

Filter Type


Koller Products TOM Aquarium Internal Power Filter (45 GPH Flow Rate)


Filter Type

Last update on 2021-10-01 / Commissions Earned / Images from Amazon Product Advertising API

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Christopher Adams

Hey there, my name is Christopher and I'm the creator and editor of this site. I've owned successful aquariums for the past 23 years. My mission is to educate, inform, and entertain on everything that's fish.

XP-03B Small Hang On the Back( HOB) Filter for Betta Fish Tank Aquariums UNBOXING \u0026 Review

Best Filters For Betta Fish: Buyer’s Guide & Reviews For Your Aquarium

Yes, that’s right bettas need a filter in their tank. Keeping optimum water conditions is arguably THE most important aspect of fish care. Something you don’t want to get wrong.


A great filter will keep your betta fish happy and healthy, plus the tank will look cleaner and your water column will stay clear. However, with the betta’s soft flowing fins there are a few things that should influence your choice. For me, I put the AquaClear CycleGuard Power Filteron top of my list for reasons you’ll soon find out below. 😉 

What follows is a closer look at filtration systems and a look at some of the best filters for betta fish:

1. AquaClear CycleGuard Power Filter1. AquaClear CycleGuard Power Filter

Multi-Stage Filtration

  • Clip-On Style
  • Waterfall Design
  • Preserves Good Bacteria
  • W/ Accessories
Click here for best price
2. Tetra Whisper Internal Filter2. Tetra Whisper Internal Filter

Quick Filter Change

  • 3-Stage Filtration
  • 2-Sided Bio-Bag
  • Anti-Clog Design
Click here for best price
3. Aqueon QuietFlow LED PRO3. Aqueon QuietFlow LED PRO

Adjustable Placement

  • 5-Stage Filtration
  • Clog Indicator Light
  • Self-Priming
Click here for best price
4. Penn-Plax Cascade Canister Filter4. Penn-Plax Cascade Canister Filter


  • 3-Stage Filtration
  • Push-Button Primer
  • Tip-Proof Base
Click here for best price
5. Eheim Classic 250 External Canister Filter5. Eheim Classic 250 External Canister Filter

All-In-1 Kit

  • Mech'l Purification
  • Bio Purification
Click here for best price

Page Contents

Five Great Filtration Choices For Your Betta Tank

1. Tetra Whisper Internal Filter For Aquariums

Using the Tetra Whisper Filter will not disturb your Betta as much as other designs will as you do not have to put your hand into the aquarium. Its cleaning cartridges are easy to access from the top of the device. You can also unclip it from the tank if you need to clean the impeller blade.

The quick-change cartridges make this system one of the easiest that you can use for your Betta fish tank. It uses a cartridge system, allowing you to change media without a mess. You should also find this product producing a limited amount of noise during operation.


  • You can select from reasonably priced systems for various sized Betta tanks
  • This may be one of the easiest systems to use for beginners
  • Tetra products are easy to find online as well as at pet shops


  • As it is an internal filter it does take up space that the fish could have been using for swimming in

2. Aqueon QuietFlow LED PRO Aquarium Power Filter

This Aqueon QuietFlow compact model will work well inside of Betta tanks that are 10-gallons or more in size. It is designed to be placed in different directions so you will have more options to work around your tank’s shape as well as the decorations.

This filtration system may be too large for the walls on some Betta fish tanks.

Not only is the direction adjustable, but you can also move the return to adjust its height. Proprietary cartridges can be purchased to offer you all three types of filter media in one package. The manufacturer also offers a limited lifetime warranty on this product.


    • It is a very quiet filter
    • It can be mounted horizontally or vertically in your betta tank
    • A patented BioGrid media works great against ammonia and nitrates


  • It can cause water current that your Betta may have to swim against

3. AquaClear CycleGuard Power Filter

This AquaClear CycleGuard filter will create plenty of oxygen in the water column, preventing your Betta from having to gain oxygen at the water surface. Your water should stay very clear due to the volume of water it will clean each hour.

You will find this product cost-effective as it offers the longest contact time between the water and filtration mediums.

A two-year warranty will provide you with the confidence to depend upon its filtration abilities. You should also come to appreciate the room in the media chamber that will allow you to mix and match the mediums that you can use.


  • This product will produce more aeration in the water column
  • It is capable of cleaning a large volume of water for the system’s size


  • There will be more water evaporation as this design exposes the water outside of your tank’s lid


4. Penn-Plax Cascade Aquarium Canister Filter


Penn-Plax Cascade should prove a good fit for Betta keepers who want a canister filter for their smaller aquariums. The motor is separated from the filtration media so you will not have to worry about them clogging your motor intakes.

The smaller canister will require cleaning more often as the chamber and its contents will clog faster than larger canister systems will.

The controls are limited by design as this system is made to operate with a minimal amount of fuss. The media chamber can be packed with any type of material you wish to use for filtration purposes.


  • It can provide three-stage canister filtration without being overkill on smaller Betta tanks
  • Priming the filter at startup is easy to do
  • Water feed hoses are located along the top of the unit


  • This product design is a bit too heavy as it has a base that tapers
  • The media chamber is smaller due to its more compact design which may be a disadvantage to some aquarists


5. Eheim Classic 250 External Aquarium Canister Filter

The Eheim Classic 250 provides mechanical and biological purification and a lot more. A strong seal allows the pressure to build evenly and creates a smooth water flow through the media used.

Eheim is one of the most popular filtration systems due to its durable design and cleaning reputation on the market.

This filter is made from strong materials that will provide years of service. Its impeller blade is damped which allows it to run silently in any room.


  • Enhances your tank’s oxygen exchange
  • Comes with accessories
  • Tested for optimal efficiency


  • This system comes at a higher price point than most other products on this list
  • Its strong seal will make it harder to break open and clean during maintenance


Betta Filtration Needs

Reasons Why You Need A Betta Fish Filter

A filter is probably the most important component of your betta tank outside of the water itself. There is a multitude of reasons that a filter will keep your Betta fish healthy and happy. The best filter for Betta will help with:

  • A filter will help to clean your Betta tank. Betta fish, even if the Betta is kept by itself, will generate debris in the water column. A Betta fish tank with a filter will be easier to keep clean and help save you time without having to remove your Betta.
  • The filter can remove toxins that build up from Betta waste. Betta tank filter medium can eliminate high levels of ammonia and nitrates. The best designs will use more than one type of filter medium.
  • Your filter will help a Betta breath as they aerate the water. The filter will expose more water to the surface, oxygenating the water for your Betta fish.

The Benefits Of Having A Betta Fish Filter Installed

Betta filter products keep the water clean, allowing both the Betta and you to enjoy the best views. This allows you to see throughout the entire Betta aquarium and presents Betta fish colors clearly. A filter will make your Betta aquarium look more presentable.

A filter allows you to go longer between (water changes) in your Betta tank. Betta fish will experience less stress with a filter and the overall health of your Betta will be improved. Your filter system will make maintenance less time-consuming, allowing you to spend more time viewing your Betta fish.

This video below will discuss that in detail: 

How Is A Betta Fish Filter Used?

A filter on your Betta aquarium takes the water from your Betta tank and runs it through filter mediums. The best filter for Betta will also help to oxygenate your Betta fish’s water column. These filter processes are done before returning the water into your Betta tank.

The filter accomplishes this by using a motor to pull or push water through the filter system. Your best option for a Betta tank will return the water without creating a strong current that the Betta fish will struggle against. Water returns from a filter system either above or below the surface in your Betta aquarium.

Depending upon the design of the filter, the housing will be placed in the Betta tank, on the aquarium housing, or outside of your Betta fish tank on a shelf.

Betta Fish Filter Designs

While there is a variety of filter systems, these designs are considered by many as the best filter for Betta:

Canister Filter Systems

This is a popular type of filter used throughout the hobby. The filter uses a pump to draw water out of your Betta tank, through the filter media, and back into the Betta aquarium. They are also referred to as an external filter for a Betta fish tank.

HOB Filter Systems

These filter products hang on the outside of the Betta fish tank glass. A filter pump draws water across the filter mediums before returning it into the aquarium. It is also called a power filter by many Betta fish enthusiasts.

Sponge Filter Systems

 It is an internal filter that sits inside the Betta fish tank. It draws water through a filter sponge that returns the water into your Betta tank. Some Betta keepers refer to these as airlift filters, as a sponge filter for Betta uses an air hose to push water through the Betta filter.

Under Gravel Filter Systems

Another type of internal filter, these products are placed under the sand substrate in your Beta aquarium. They use the substrate as a filter media, drawing water below the sand and through tubes that return the water into your Betta fish tank. This filter system also uses air for water circulation.

Best Betta Fish Filters To Look For

Flow Rate

By far the most important feature of a Betta tank filter will be the amount of water it cleans. This will be measured by Gallons per Hour, and the best designs will cycle the entire betta tank at least three times each hour.

Filter Media

These come in biological, chemical, and mechanical forms. The best filter for Betta will use two, preferably all three, media types.

Noise Level

You and your Betta will benefit from lower noise output from the product. The best filter for Betta will generate lower decibel levels.

Ease Of Use

Less complicated systems are easier for beginning Betta keepers to use. Your best filter for Betta should be easy to clean and require little input to operate.


All of the products listed above will offer clean water for your Betta to enjoy. With that being said, we feel that the greatest overall filter for AquaClear CycleGuard Power Filter.

It is a quiet filter that is suitable for tanks up to 10 gallons – which is a great size for a betta fish. The shape and ability to set up the filter vertically or horizontally means it is suitable for most displays and arrangements.

You fish will enjoy fantastic water conditions due to the filter’s three different types of filtration.

Plus a limited lifetime warranty!

Last Updated: October 17, 2021

Aqueon Quietflow Filter Review


Betta filter small

Contrary to popular belief, betta fish should never be kept in those tiny – though adorable – fishbowls or uniquely shaped tanks that only hold a couple of gallons.

And they should have properly treated, filtered water that removes the toxins and debris that can severely shorten a betta’s lifespan.

So, the question becomes, what does a betta need? Is a filter necessary at all? What kind of filter? Why do they need them anyway?

Below we’ll break down our reviews of the best filters for betta fish.

Best Betta Filter Quick-Find Table




Hikari Bacto-Surge

  • Very quiet while being very effective
  • Perfect for smaller aquariums and fish tanks
  • Nearly zero flow for still water settings
  • Very quiet while being very effective
  • Perfect for smaller aquariums and fish tanks
  • Nearly zero flow for still water settings

Marina Slim S10

  • Self-priming for extremely easy setup and install
  • Very easy to maintain and clean
  • Adjustable flow rate
  • Self-priming for extremely easy setup and install
  • Very easy to maintain and clean
  • Adjustable flow rate

Lee’s Premium

  • Resists splitting and cracking
  • Super easy to install and maintain
  • Great for larger aquariums
  • Resists splitting and cracking
  • Super easy to install and maintain
  • Great for larger aquariums


  • Suitable for breeding tanks, as well as standard betta tanks up to 10 gallons
  • Low profile – won’t detract from aesthetics of your aquarium
  • Provides both biological and mechanical filtration in one
  • Suitable for breeding tanks, as well as standard betta tanks up to 10 gallons
  • Low profile – won’t detract from aesthetics of your aquarium
  • Provides both biological and mechanical filtration in one

Why Do Betta Tanks Need Filters?

Beginner hobbyists tend to think that certain fish don’t need as much care simply because they’re low maintenance. We hear all the time, “Goldfish are fine with a bowl and some simple flakes. They’re cold water fish, so who needs anything else?”

best betta tank fish filter

But both betta and goldfish, along with other pet fish, need to be kept in healthy, clean, pure aquarium water. Some need the added element of marine salt, but freshwater fish also need that pure, filtered water just as much.

A betta’s natural habitat looks like rice paddies and shallow, brackish bodies of water.

These little Asian fish can actually gulp oxygen from the air – thus why they sometimes go to the waterline – instead of relying solely on their gills.

This is because the betta fish has a labyrinth organ, which allows this combination breathing.

This all means they have a high tolerance for low oxygenated water.

Because of all of this, bettas are easier to care for than some of the other tropical fish that are popular in aquariums. They require less equipment in their homes and that can make them easier to care for.

But they still need the pure, filtered water that doesn’t contain any of the stuff that tap water has in it.

Healthy Betta Habitats

Let’s address a critical point here.

Betta fish need to be kept in at least 5 gallon tanks per each betta.

And each betta should be kept separately, especially males.

The other name for betta fish is Siamese Fighting Fish. There’s a good reason for that.

These fish are extremely territorial – even the sight of another betta can set these beautiful little guys off.

Types of Betta Tank Filters

Betta tank filters can come in a variety of types. You just have to determine which option is most useful to your fish keeping style.

The different kinds of filters work differently and may be appropriate for one size tank more so than another. They may also be more appropriate for a given fish keeping style more so than another.

Under Gravel Filters

This type of filtration lives up to its name: they rest under the gravel. Under gravel filters use biological filtration – i.e. good bacteria – to filter out unwanted crud in the aquarium water.

Hang on Back – HOB – Filters

Hang on back, or HOB, filters do as they say. The filter hangs on the back of the aquarium, semi-submersed, for a thorough filtration process of your aquarium water.

These are probably the most convenient, thorough filters for most people to use. They’re also less invasive with a reasonably low profile to prevent taking away from the aesthetics of most aquariums.

Sponge Filters

Sponge filters are great for getting debris from the aquarium water.

They’re the “first” level of filtration – mechanical filtration – but need to be paired with other filtration for a thorough, deep filtration for the healthiest aquarium environment possible.

Canister Filters

Canister filters are an external, inline filtration system that usually resides in the sump.

Submersible or Internal Filters

These filters are basically a drop-in option that filters the water inside the tank. They tend to have weighted bottoms to keep them from floating, though some folks use suction cuts to keep them in place.

Filtration Media Types

Beyond the type of filter, there are filtration types that play an important part in keeping your aquarium water pure and clean.

Mechanical Filtration

Mechanical filter media is made with porous, inert materials that remove particles from the water – like waste and sludge – capturing the crud in its fibers.

This media is sort of like a fish net.

The water passes through the mechanical filter media, removing debris through a straining process.

Mechanical media can be everything from coarse to very fine material, which effectively traps the particles and removes them from the water.

This kind of filter media comes in a range of forms, including sponges, pads, and blocks, made from a range of materials, including filter wool. Mechanical filtration is required to remove dust, uneaten food, fish wastes, and dead plant pieces from the water.

Close-up underwater view Siamese Fighting Fish isolated on white

Biological Filtration

The next phase of filtration is biological. Biological filtration media can kind of be thought of as like a house. Inside the house, healthy bacteria lives. This beneficial bacteria kills off the bad bacteria that lives inside your aquarium. It also helps to kill off ammonia and eliminate fish waste, uneaten fish, et cetera.

Ammonia is deadly for your fish. As it builds up in the aquarium, the ammonia eating bacteria housed in the biological filter media. This good bacteria reproduces and then consumes the ammonia, giving off nitrites. The nitrites also need to be eliminated, so the other kind of good bacteria takes care of it.

The two types of bacteria team up to maintain the healthy balance inside your aquarium environment.

Biological filter media comes in an even wider range of materials and types than mechanical filtration media. Bio-balls, foam, ceramic and glass rings, pelleted carbon, plastic pieces, et cetera, can all be the “house” in which the good bacteria live.

Chemical Filtration

The final type of filter media, which may or may not be used in a betta tank, is chemical filtration. This type of filtration is a specialized chemical additive that removes specific impurities from your fish tank water. Some target chlorine, chloramine, copper, odors, and other water impurities.

Carbon chemical media removes copper, chlorine, carbohydrates, and dissolved chlorine, along with other impurities. It also removed dis-colorants from the water, improving and increasing the clarity of the water.

Water Flow and Reducing Current

Because bettas naturally live in a low flow environment, it’s important to get a low flow filter for betta tanks.

So, there are a few things to keep in mind for controlling the water flow and reducing the current.

1. Buy a Filter with Adjustable Flow Control

The first and easiest way to make sure you can reduce the current in your aquarium is through choosing an aquarium filter than has an adjustable flow control.

This will make it easier to guarantee the flow rate will be low enough that your betta’s life won’t be too disrupted.

2. Create a Flow Baffle

If you’re not able to buy a filter with the adjustable flow rate, you can help to disperse the flow of water by making yourself a baffle.

This can be anything that blocks or redirects the water coming from the filter. A simple tank divider kit, which includes a mesh screen and attached mechanisms, is one of the easiest ways to create this baffle.

Or, you can use a plastic soap dish or shower caddy that attaches with suction cups.

3. Block the Filter Intake

Use your in-tank décor to create a sort of block for your water flow.

This is kind of an oasis in the tank, which helps to protect your betta from a heavier flow than preferred.

Red Siamese Fighting Fish isolated on white

How to Choose the Best Filter for Betta Fish

There’s no definitive “best filter for betta fish” in generic terms. There are, instead, multiple factors to consider for your specific betta tank setup.

You’ll need to consider things like aquarium size, number of fish/tank mates with your betta, output rate, plants you keep, durability, quality of manufacture, and how the filter will affect the aesthetics of your aquarium.

  • Low flow output and current – for the comfort and low stress levels for your betta
  • Easy to maintain/use – easy to remove cartridges, easy to replace, easy to clean set up
  • Quality of performance – does it do the job? Does it actually keep your aquarium clean?
  • Filter media types – at minimum both mechanical and biological are necessary for a healthy aquarium
  • Reliability, durability, quality of manufacture – Does the filter perform consistently? Does it clog easily? Is it well made?

Reviews of the Best Filter for Betta Tanks

We looked for the above criteria to find the best filter for betta tanks. Each option listed below considers the quality, make, reputation of the brand name, and the options that make a given filter better than another for a betta tank.

Hikari Bacto-Surge High Density Foam Filter

The Hikari Bacto-Surge high-density foam filter from Aquarium Solutions is a fantastic option for general betta tank filtration.

This is a super quiet option – which makes it great for offices, bedrooms, and any other spaces where you need a low volume profile, while doing all that it promises it will.

  • Flow rate: Very low – almost zero
  • Tank size: 5 to 15 gallons
  •  Media type: Biological filtration, foam

What We Loved

The first thing that we absolutely love about this particular filter for use in a betta tank is that it’s a filter that doesn’t actually pump any water. That means it doesn’t create some kind of current that will disturb your betta. Instead, it produces a small stream of bubbles as it works.

It’s also an extremely quiet filter, which automatically makes it a winner for any aquarium, but especially for small fish tanks where hefty noises may bother your fish.

The filter has a weighted bottom, so it’s a great submersible – or internal – filter that stays put.

We also love that this really does the trick in cleaning up planted aquariums and murky tanks quickly.

What We Didn’t Love

The only thing we’ve really seen any potential problems on this for is that it’s a bit chunky for the sizes of aquariums its really most appropriate for.

It is extremely quiet and mostly un-intrusive for the fish, but it’s not the prettiest thing you’ll see in your aquarium.

Most fish keepers using it recommend surrounding it with plants and decorations to make it less obvious.

Our Verdict on the Hikari Bacto-Surge High-Density Foam Filter

The Hikati Bacto-Surge is a really great biological filter for your betta fish tank.

It’s uber quiet, very easy to use, works really well, and generally just does everything you’d want in a betta filter.

It’s even very low flow rate, which makes it perfect for your still water fish like bettas and goldfish who naturally live in slow flowing ponds and stagnant puddles.

The only drawback is that it isn’t the smallest option out there and some find it a bit of a nuisance. But if you surround it with plants and decorations, you probably won’t even notice it.

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marina slim s10 filter for bettas

The Marina Slim S10 Power Filter is an extremely easy to maintain, easy to clean, self-priming HOB filter that comes from one of the most well-trusted brands on the market.

The filter is extremely compact and slim, making it ideal for small tanks – such as 5-gallon tanks – and tucks away neatly into the background, leaving the aesthetics of your betta tank practically untouched.

  • Flow rate: Low to mederate, adjustable
  • Tank size: Up to 10 gallons
  • Media type: Biological, ceramic

What We Loved

The Marina Slim S10 is a really fantastic HOB filter for your betta tank for a number of reasons.

First off, it provides you with a decent flow rate that’s adjustable, meaning you can tweak it for the needs of your betta tank. It’s reasonably powerful, though, so you may need to use a baffle.

It’s super easy to clean and maintain, which, combined with the flow rate, means you’ll have an uber clean, safe aquarium for your beloved betta fish.

The filter also uses the more effective ceramic filtration media, which surpasses most sponge filters. This means your betta’s health will be even more improved.

Plus, the filter is super easy to install, use, and maintain throughout its life, which makes it a great option for beginner aquarists or life-long hobbyists alike.

What We Didn’t Love

The only potential drawback on the Marina Slim S10 is that it’s a bit pricier than some of the other options.

But because it’s a much higher quality filter media, that’s not much of a sacrifice.

It just may not be the most viable option for folks on a super tight budget.

Our Verdict on the Marina Slim S10

The Marina Slim S10 is honestly just about the best darn biological filter you can get for your betta tank.

The slim, sleek look of it makes it a more attractive option since it won’t take away from the aesthetic quality of your betta tank, plus it uses higher quality filtration media than most.

It’s a little pricier, but for anyone not on a super tight budget, that shouldn’t be too big of a deal, since it’s well worth the price.

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Lee's 40/55 Premium Undergravel Filter

Lee’s 40/55 Premium Under Gravel Filter is a top-notch choice for anyone keeping betta in a larger aquarium – 40 gallons or larger.

They’re made of extremely high-quality plastic – built for durability and prevention of splitting and cracking – and last a long time.

  • Flow rate: Low to moderate
  • Tank size: 40 to 55 gallons
  • Media type: Biological & chemical, active carbon

What We Loved

Lee’s Premium under gravel filter plates have eight port tubes, which is fantastic for versatility as you may need.

This filter also comes with four active carbon filter cartridges, which we love, because that means it’s taking care of both the biological filtration and chemical filtration needs for your betta tank.

We also love that thanks to those ports, you can use extra filter tubes to connect to external filters, which can prevent fish fry and other things from getting sucked up into the filter.

It’s especially great for anyone who keeps betta fish with any critters that scoops of sifts in the gravel and sand, because of the particular makeup of the plates and how they’re positioned in the tank.

We also love that the extra ports come with caps, to prevent other issues. Just be aware that once the caps are one, they’re pretty much on for good.

What We Didn’t Love

Most of the complaints we’ve seen are pretty limited to specific circumstances and preferences, but a few things we found that others don’t love include:

  • Though the 4 carbon cartridges are great, not everybody wants them, and they add expense.
  • You can’t really use an under-gravel filter as your only filtration system for your aquarium, so you’ll need to use this in tandem with some other filter.
  • There are gaps between the plates, which can be annoying for some, though not a critical issue.
  • Some people think the tubes are too long.
  • Some people think the tubes are too short.
  • Some folks found the carbon cartridges difficult to attach.

Our Verdict on the Lee’s 40/55 Premium Under Gravel Filter

If you keep a larger betta tank – 40+ gallons – you’ll find that Lee’s Premium under gravel filter is a great option for adding both biological and chemical filtration without a hassle.

The filter has eight ports for great versatility and ease of placement, is made of extremely high-quality plastic that won’t split or crack, comes with 4 carbon cartridges for filtration, and generally just works really well.

There are some qualities about it not everyone loves, but these are pretty much preferential things rather than actual issues. So, all-in-all, this is a great option for anyone with a larger betta fish tank.

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XY-2831 Air Pump Sponge Filter for Aquarium

The XY-2831 Air Pump Sponge Filter is the best filter you’ll find for your 10-gallon betta tank.

It provides you with both mechanical and biological filtration – meaning less hassle and fewer filter devices – is safe for breeder tanks or small fish and is low-profile enough that it won’t mess with the general appearance of your aquarium’s look overall.

  • Flow rate: Low to moderate, adjustable
  • Tank size: Up to 10 gallons
  •  Media type: Biological, mechanical, foam/sponge

What We LoveD

First off, we love the price of this filter. It’s stupidly inexpensive, but still does all that it’s supposed to do for your betta tank. It’s really high-quality, especially when you keep the extremely budget-friendly price in mind.

The filter not only works as a biological and mechanical filter, but it also provides you with some aeration. This is great for most aquariums, though you may need a baffle in the tank with your betta, and you will, of course need to buy the air pump to process the power properly.

This particular filter provides your beneficial bacteria a ton of space to collect on, which is fantastic. That means you can grow a ton of it, which in turn means it kills off the bad stuff more effectively and efficiently.

We also love that this is a really safe filter to use with very small fish – including fry – and sensitive critters. The filter won’t suck up anything too large, so your little pals are safe.

What We DIDn’t Love

We couldn’t really find much wrong with this filter. In fact, it’s practically perfect for a small aquarium.

Just be sure to thoroughly wash the suction cups before installing as some folks noted that they got a film off the suction cup the first time they installed.

Our Verdict on the XY-2831 Air Pump Sponge Filter

All in all, this is a truly fantastic filter for anyone to use in their betta tank. It’s uber budget-friendly – anyone can afford it! – and works well.

It’s easy to install, easy to maintain, and really does the trick with both biological and mechanical filtration. Just be sure to wash the suction cups thoroughly before installing, and you’ll be golden.

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Betta Filter FAQs

How often do you need to clean it?

Most of the time, you want to clean your betta tank filter about every 10 days. You should never do this with tap water, hot water, or distilled water, however.

They should only be “cleaned” with the existing aquarium water to avoid killing off the beneficial bacteria you’ve got in there.

Are sponge filters any good?

Some sponge filters are good, some are not. It really depends on the brand and quality of the manufacture. If you choose foam or sponge filters, only go with ones from companies you already know and trust – or that long-time aquarists do if you’re a newbie – or ones that have very high ratings from real-life users on sites like Amazon.

Do filters hurt bettas?

Generally speaking, filters do not hurt fish. The circumstances under which this may be different, however, is if you have delicate fins – like bettas – with a filter that’s too powerful for the environment.

Be sure to always size your filter to the number of gallons of water in your aquarium.

Can bettas live in a bowl without a filter?

Bettas should never live in a fishbowl. They need at least 5-gallons of water per betta.

And technically, bettas can live in small fish tanks without filters, but they are likely to merely be surviving if they do. Use filters to keep their homes safe, pure, and healthy for them for a long lifetime.

The BEST Aquarium Filter for BEGINNERS?
Published: April 27, 2021 - By: Lucas - Categories: Equipment

Filters are an essential piece of hardware in nano tanks of 5 gallons or less. The small volume of water in these tanks means effective filtration is extremely important to the health of your livestock. Here you can find information on a variety of makes, models, and types of filters to help you choose a good quality and reliable option.

Best filters for nano fish tanks up to 5 gallons

ModelOur ratingTypeFlow rateIdeal forMedia
Aqua Clear 20 power fish tank filtereditor's ratingAqua Clear 20 power fish tank filter #adHang-On-Back100 GPH, adjustable5-20 gallonsFoam, Activated Carbon, and BioMax
Azoo Mignon 60 Power Filtereditor's ratingAzoo Mignon 60 Power Filter #adHOB16 GPH, adjustableup to 3.5 gallonsfilter pads
Penn-Plax Small World Aquarium Filter (SWF1)editor's ratingPenn-Plax Small World Aquarium Filter (SWF1) #adinternal filterair pump powered (buy separately)up to 5 GalBio Sponge, Carbon, and Zeolite
Marina S10 Power Filtereditor's ratingMarina S10 Power Filter #adHOB55 GPH, adjustableup to 10 gallonsfilter cartridges with included carbon & zeolite
Aquatop Classic Aqua Flow Sponge Filter CAF-10editor's ratingAquatop Classic Aqua Flow Sponge Filter CAF-10 #adSponge filterair pump powered (buy separately)up to 10 Galsponge
Aqueon Quietflow E Internal Power Filtereditor's ratingAqueon Quietflow E Internal Power Filter #adinternal filter25 GPHup to 3 gallonscarbon cartridge
Finnex Pure-5 Power Aquarium Filtereditor's ratingFinnex Pure-5 Power Aquarium Filter #adHOB30 GPH, adjustableup to 5 gallons1 pcs filter cartridge included
Marina I25 Internal Filtereditor's ratingMarina I25 Internal Filter #adinternal filterup to 6.6 gallons (25 L)filter cartridge with included carbon & zeolite
NO.17 Submersible Aquarium Internal Filter 6Weditor's ratingNO.17 Submersible Aquarium Internal Filter 6W #adinternal filter132 GPH (500 L/H), adjustable1-10 Galsponge
Tetra Whisper 4i Internal Filtereditor's ratingTetra Whisper 4i Internal Filter #adinternal filter27 GPH4 Galsmall Bio-Bag cartridge

Small aquarium filter reviews

Aqua Clear 20 power fish tank filter

The more time your aquarium water spends in contact with your filter media, the cleaner it’s going to be. With this in mind, AquaClear has designed this power filter to use 3 different media, providing chemical, mechanical, and biological filtration to preserve beneficial bacteria.

This unit has excellent filtration volume and ensures that the water surface remains broken, which is essential for introducing available oxygen to the system. This model also features adjustable flow control that gives the aquarist greater control of the environment to suit the biotype and species in their aquarium.

Azoo Mignon 60 Power Filter

  • Azoo Mignon 60 Power Filtereditor's ratingCheck on Amazon #ad
  • Type: HOB
  • Flow rate: 16 GPH, adjustable
  • Ideal for: up to 3.5 gallons
  • Media: filter pads

The Azoo Mignon 60 Filter is ideal for the nano fishkeepers out there. This filter has a compact, attractive design, and super quiet, energy-efficient performance. It is important to consider the flow rate of your filter when setting up a small aquarium, especially for fish like bettas that don’t enjoy a strong current. To make your life easier, this filter has an adjustable output that can be easily adjusted with a dial.

Azoo Mignon filter componentsAzoo Mignon filter components #ad

Not only is the output adjustable to safe levels, but the design of this filter also ensures that the intake is safe. Small livestock and weaker swimmers can easily be sucked into a powerful filter or become stuck on the intake, but this unit comes with a handy prefilter sponge that fits securely over the intake, meaning your livestock will be safe.

Azoo Mignon filter media detailAzoo Mignon filter media detail #ad

The Azoo Mignon 60 Power Filter comes with 2 easy to replace filter pads, for mechanical and biological filtration, but you can also easily custom fit your own filter media into the chamber. Just be sure not to overfill the compartment with a dense medium as this could put extra strain on the built-in motor.

 Penn-Plax Small World Aquarium Filter (SWF1)

  • Penn-Plax Small World Aquarium Filter (SWF1)editor's ratingCheck on Amazon #ad
  • Type: internal filter
  • Flow rate: air pump powered (buy separately)
  • Ideal for: up to 5 Gal
  • Media: Bio Sponge, Carbon, and Zeolite

The Penn-Plax Small World aquarium filter is an extremely compact internal air-powered filter that works well in a variety of tank shapes, including rounded designs and bowls. This unit is specifically designed for use in small aquatic habitats and tanks of up to 5 gallons.

Penn-Plax Small World Aquarium Filter side viewPenn-Plax Small World Aquarium Filter side view #ad

Being an internal air-powered filter, you will need a small air pump and some airline tubing, which are sold separately, to operate this filter. This model is suitable for both acrylic and glass tanks and can be used in both fresh and saltwater. The green and clear plastic design of this filter does not stand out strongly and works especially well with natural green aquascapes.

The Penn-Plax Small World Aquarium Filter includes a disposable filter media cartridge with carbon and zeolite crystals, as well as a bio sponge, ensuring that effective biological, chemical and physical filtration takes place.

Penn-Plax Small World Aquarium Filter suction cupsPenn-Plax Small World Aquarium Filter suction cups #ad

This filter is very easy to install, using the 2 suction cups on the filter mounting bracket. The strength of the current created within your aquarium will depend on the size of the air pump used and it is a good idea to use a bleed valve or an airline control valve to adjust the flow.

Marina S10 Power Filter

  • Marina S10 Power Filtereditor's ratingCheck on Amazon #ad
  • Type: HOB
  • Flow rate: 55 GPH, adjustable
  • Ideal for: up to 10 gallons
  • Media: filter cartridges with included carbon & zeolite

The Marina S10 Power Filter is one of the best hang-on-back (HOB) filter options for fishkeepers with limited space around their tanks. This great-looking filter is suitable for tanks of up to 10 gallons and has a fully adjustable flow to suit the size of your aquarium, and the kinds of fish and animals you keep.

Marina S10 Power Filter top viewMarina S10 Power Filter top view #ad

The Marina S10 Power Filter comes with a bio-clear and bio-carb filter, which are very easy to replace, saving you time and effort on maintenance. Being a hang-on-back (HOB) filter, this unit takes up very little space inside your aquarium and it has an innovative design that incorporates the motor on the inlet pipes, meaning the motor is housed under the water surface for quieter operation.

Marina S10 Power Filter cartridgesMarina S10 Power Filter cartridges #ad

This is a self-priming filter which means you don’t have to fill the compartment before restarting the unit after a power failure. In order to protect your livestock, this model includes a prefilter sponge which means small animals won’t become trapped within the filter during operation.

Aquatop Classic Aqua Flow Sponge Filter CAF-10

  • Aquatop Classic Aqua Flow Sponge Filter CAF-10editor's ratingCheck on Amazon #ad
  • Type: Sponge filter
  • Flow rate: air pump powered
  • Ideal for: up to 10 Gal
  • Media: sponge

The Aquatop Classic Aqua Flow Sponge Filter is a simple but effective internal air-powered filter for a Betta, or shrimp and snail tank that needs low water flow. This filter provides mechanical and biological filtration and has the added benefit of increasing oxygen levels in your tank.

In order to run this filter, you will need a small air pump (buy separately) and a length of airline hose. This style of filter does not produce any strong suction that could trap or injure your fish or livestock. Although the sponge of this filter provides plenty of surfaces for beneficial bacteria to colonize, it is also possible to add a further filter media of your choice to the compartment for customized filtration.

Aqueon Quietflow E Internal Power Filter

  • Aqueon Quietflow E Internal Power Filtereditor's ratingCheck on Amazon #ad
  • Type: internal filter
  • Flow rate: 25 GPH
  • Ideal for: up to 3 gallons
  • Media: carbon cartridge

The Aqueon Quietflow E Internal Power Filter can be hung from the rim of your aquarium in a similar way to hang on back (HOB) filters or simply attached to the inside of your tank using the suction cups. Once installed, the unit can be left to run and will automatically restart after power interruptions.

As is indicated by its name, this filter is very quiet and economical with power consumption. The carbon cartridge used provides effective chemical filtration, while beneficial bacteria colonize the sponge for vital biological filtration. This is a great option for nano tanks of up to 3 gallons.

Finnex Pure-5 Power Aquarium Filter

  • Finnex Pure-5 Power Aquarium Filtereditor's ratingCheck on Amazon #ad
  • Type: HOB
  • Flow rate: 30 GPH, adjustable
  • Ideal for: up to 5 gallons
  • Media: 1 pcs filter cartridge included

The Finnex Pure-5 Power Aquarium Filter is a hang-on-back (HOB) power filter that can effectively filter up to 30 gallons per hour, although the flow rate is adjustable, meaning you have the power to dial it in to suit your needs.

This filter has extendable intake tubes and is suitable for both freshwater and saltwater tanks. The included carbon cartridge and sponge provide mechanical, biological, and chemical filtration, and are easy to change.

Marina I25 Internal Filter

  • Marina I25 Internal Filtereditor's ratingCheck on Amazon #ad
  • Type: internal filter
  • Flow rate:
  • Ideal for: up to 6.6 gallons (25 L)
  • Media: filter cartridge with included carbon & zeolite

The Marina I25 Internal Filter is suitable for use in aquariums up to 6.6gallons. The unit is easily installed with the provided suction cups, and once running, will effectively filter your aquarium through biological, mechanical, and chemical action.

This 3 stage filtration process makes use of zeolite and carbon to ensure, safe, crystal clear water without any unpleasant odors. The filter cartridges are quick and easy to replace and one of the great benefits of compact internal filters like the Marina i25 is the very low noise levels created since the motor is submerged.

NO.17 Submersible Aquarium Internal Filter 6W

  • NO.17 Submersible Aquarium Internal Filter 6Weditor's ratingCheck on Amazon #ad
  • Type: internal filter
  • Flow rate: 132 GPH (500 L/H), adjustable
  • Ideal for: 1-10 Gal
  • Media: sponge

The NO.17 Submersible Aquarium Internal Filter is highly corrosion-resistant, making it suitable for use in both fresh and saltwater aquariums. The unit is capable of filtering an impressive 132gph but is adjustable to reduce the flow rate.

By attaching a short length of hose to the filter’s output nozzle, you can add aeration to the output. This has the effect of reducing the flow rate further and increasing oxygenation in your tank.

Tetra Whisper 4i Internal Filter

  • Tetra Whisper 4i Internal Filtereditor's ratingCheck on Amazon #ad
  • Type: internal filter
  • Flow rate: 27 GPH
  • Ideal for: 4 Gal
  • Media: small Bio-Bag cartridge

TheTetra Whisper 4i Internal filter by Tetra is suitable for nano aquariums of up to 4 gallons. The flow rate of this aquarium is fixed at 27gph which is not overly strong and the unit is attached using the supplied suction cups.

This filter produces very low noise levels and makes use of both cartridge floss and ultra-activated carbon to provide both mechanical and chemical filtration

How does a filter work?

Filters are designed to clean the water in your fish tank, to keep it clear, odorless, and safe for your fish and plants to live in. Filters work by pushing water through filter media in order to clean it before returning it to the tank. There are 3 basic types of filtration that modern fish tank filters use.

Biological filtration

Biological filtration is probably the most important type of filtration for your aquarium. Even though the water in an aquarium may look crystal clear, if it has not been cycled, it may be very harmful to the fish that live in it. In a correctly established and cycled fish tank, beneficial bacteria will colonize the sponge in your filter and work to change harmful ammonia and nitrites in the water into harmless nitrates.

Mechanical Filtration

This type of filtration involves the physical removal of particles like fish waste in the water. These particles will collect in your filter over time and can be rinsed out of your filter media or you can replace disposable filter cartridges.

Chemical filtration

Substances such as activated carbon and zeolite are also often included in aquarium filters. These materials are able to trap and neutralize harmful chemicals such as ammonia and chlorine in the water to provide a safer environment for your fish and other livestock.

Frequently Asked Questions

Do I need a filter for my betta?

All fish require filtered water to stay happy and healthy in home aquariums. While some experts are able to keep their water clean without electrically powered filtration, this is not recommended for beginners, especially not in the small aquariums that bettas are usually kept in. At the end of the day, all responsible fish keepers should care for the health of their livestock and even though bettas are tough fish that can live for some time without a filter, you should use one in your tank.

Do I need to do water changes if I have a filter?

With a small aquarium, you should get into the habit of doing partial water changes every week. Provided you have not overstocked your aquarium, weekly water changes of around 25% are advised because your filter can not remove all the waste in your tanks.

Do I need to clean my filter?

Over time, your filter media will become clogged by waste and particles in the water. Many power filter models incorporate disposable filter cartridges that should be changed at the frequency advised by the manufacturer.

You should not replace all of your filter media at once as this will remove the beneficial bacteria that are essential for biological filtration. Reuseable filter media such as sponges should be rinsed in tank water that you have removed during a water change to preserve these bacteria.

What flow rate do I need?

Generally speaking, your filter should have an hourly flow rate of at least 4 to 6 times the volume of your aquarium to be effective. Some fish species are adapted to live in strong currents and will enjoy a good flow rate, while fish such as bettas are easily stressed in fast-moving water.

Often it is difficult to keep a low flow rate in very small aquaria and you should select a filter with an adjustable flow rate if keeping fish that do not enjoy strong currents.

Final Thoughts

Perhaps the most important piece of hardware for a healthy fish tank is a quality filter. With so many options out there, choosing the best one for your tank can be difficult. All of the filters in this article make great choices for tanks of less than 5 gallons and if used correctly, will keep your correctly stocked and managed aquarium looking beautiful.

Lucas has been keeping successful fish, planted, and reef tanks for many years. He loves to collect aquatic organisms and keep as many aquariums as he can.


You will also be interested:

The Best Filter For A Betta

We hope that this page will tell you everything you need to know about finding the right filter for your betta aquarium. If you already have a filter, we would love to hear about the filtration setup that you’ve created, so please let us know in the comments.

This article mainly refers to choosing a filter for a tank with a single betta. For larger setups, you may need to look at a slightly different filtration system, although most of the logic still applies.

If you’d like a bit more information on how a filter works, see our betta filtration article, which includes diagrams, defines the terminology that we use, and answers some common questions.

What’s the Best Filter for a Betta?

There is no particular filtration unit that is ‘the best’ for a betta. There are several factors to consider when choosing a filter, including size, output rate, plants, tank mates, and the extent to which it will keep your aquarium clean. Therefore the ‘best filter for a betta’ will depend on your aquarium set up.

In this article we will talk about the different scenarios in which you could be choosing a filter, and present some advice that should help you to make a decision when it comes to buying. At the moment there are two filters in particular that we recommend, although it is useful to consider the recommendations within the context of the rest of this article, and to some extent our other article on filtration.

So for the impatient amongst you here are our two main recommendations, but please read the rest of the article to understand more about betta filtration.

So, on to how to choose the best filter for a betta…


Something to bear in mind when it comes to betta care (and fish keeping in general) is that there is no set way of doing things. There are certain practices that you should follow, but betta keeping also involves some degree of experimentation. This is very true of filtration — there are different things that you can try in order to achieve the optimum solution for your particular aquarium. What we’ve included below is advice based on our own experience, but we do urge you to do further research yourself.

We love to hear about the setups that other people have created, so do let us know in the comments about your filtration system, or any other aspect of betta keeping that you would like to talk about.

The best filter for a betta will have these features:

  • A slow output/current so the fish can relax and swim easily in the aquarium.
  • An easy-to-remove cartridge system – the filtration media can easily be replaced when needed, and on an individual basis.
  • Removal performance – will the filter be able to do it’s job given the size of your aquarium? Will it be capable of cycling the aquarium successfully and will it remove unwanted chemicals and waste?
  • Filter media – does it have more than one media? In some cases, having all three types of media (mechanical, bio, and chemical) is better. In other cases (such as for optimal plant growth), just having one or two is better. We cover this in more detail below.
  • Reliability – Will the filter consistently perform? Is it likely to clog-up or break down? Is it manufactured well? Always take other people’s’ experience with specific products into account when choosing a filter.

Other Important things to consider

The size of your aquarium. You may pick up a filter that is perfect in terms of the filtration mediums that it offers, but has a strong output rate. A strong output rate may not be an issue if you have a large aquarium, but can be a problem if your tank is small. In a large aquarium there will be areas where a current does not affect the water, nor create ripples on the water’s surface, which will be a suitable environment for your betta as there will be parts of the aquarium where it can escape the current, and therefore it won’t be stressed.

Does the filter have an adjustable output?  It’s important to adjust the output of a filter in relation to the aquarium size. If you add a filter with a strong output to a small aquarium, it will stress your betta. It’s therefore important that your filter either has the option for the output to be adjusted, or that you can modify the filter yourself (see our article on filter baffling) in order to control the output.

Aesthetics & Practicality. Others features that are not important to the well-being of the fish but may be important to the keeper are aesthetics and practicality. Does the filter look good? Will the filter be noisy? Will it disturb you if the filter were to make noise because of trickling, the sound of the pump, etc.? These concerns are of course secondary to the well-being of your fish, but they are still worth taking into consideration when you buy a filter.

Filter media

The typical aquarium filtration system will be comprised of three different mediums; biological, mechanical and chemical. Each one of these mediums does its own job, you can read about how they work on our filtration page..

Ideally you want to be able to replace each type of media individually because each medium needs to be replaced at different intervals. This is why a filter with separate inserts is often preferable to a filter that uses cartridges, which we explain in more detail below.

The optimum filter for a betta will contain all three mediums, although a filter with only 1 or 2 of the mediums can still perform well depending on your set up. Whilst the typical filter will be shipped with all three mediums, there are some filters that are only shipped with one or two. We’ll talk about this in more detail below, but first of all let’s look in more detail at why a cartridge filter isn’t always optimum.

Why a cartridge isn’t always optimum

Most aquarium filters these days come with all 3 filtration mediums, which is referred to as 3-stage filtration. The three mediums are known as mechanical, biological and chemical. It’s pretty standard for any built-in aquarium filter to have all three mediums, with each being easily removable and replaceable.

You may, however, come across a filter that has a replaceable cartridge. The cartridge will be manufactured by the aquatics company to fit the filter in question. Beware, though; replaceable cartridges aren’t always the best option because they can be impractical when it comes to changing the mediums at different intervals. Whilst they have been manufactured with the convenience of the fish-keeper in mind (because theoretically it’s easier to just slot in a new cartridge than it is to replace each medium individually), this can limit the control you have over the chemistry of your water. In our list of recommended filters below, we have taken this into consideration.

If you want maximum control over your betta’s water quality, it’s best to aim for a filter that has removable and replaceable individual inserts.

Filter Cartridges and Maintenance

Some filters will need to have their cartridge or inserts changed every month or so. The cartridge can vary from filter to filter, but typically a replaceable-cartridge filter will have a carbon or carbon-mixed cartridge that will need replacing periodically. Carbon is a great medium for removing toxins from the water, but if it’s not removed on a monthly bases it can actually create a backlog and the toxins can leak back into the aquarium.

The sponge insert can vary in size in any filter. When it should be rinsed/cleaned will be dependant on the amount of livestock in your aquarium. The more livestock, the more often it should be rinsed. The mechanical sponge is a place for beneficial bacteria to flourish in the filter, that’s why it’s best not to replace it. In fact, it only needs to be replaced if it gets withered over time. It should only ever be removed, rinsed (with freshwater) and reinserted. Most mechanical filtration media is hardy and isn’t designed to wither, and it usually lasts for years at a time. The same goes for biological media — nothing lasts forever but it should rarely be replaced, if at all. Over time biological media may become decrepit, but it will take years for this to happen.

Aquatics companies manufacture cartridge filters in different ways, but it’s generally agreed upon that a cartridge filter is second best to a filter that allows inserts for separate mediums. See our filtration page for definitions of this terminology and explanatory diagrams.

Choosing a filter

Now that we’ve covered the various aspects of filtration that you need to be aware of, let’s have a look at the scenarios in which you may be choosing a new betta filter.

Scenario 1: Choosing an aquarium with a built-in filter

If you’re buying a tank that comes with a filter built-in, you need to do some research to check that both the filter and tank will be suitable for the setup that you want. For instance, you may wish to check that the filter has a cartridge with separate inserts for each medium, as opposed to two mediums combined within one cartridge. This shouldn’t be the case for most tanks that come with a filter built-in, but it’s worth checking.

The majority of standard freshwater aquarium filters, especially those pre-fitted in an aquarium, tend to contain a biological, mechanical and chemical medium. From our experience, most of the in-built filters in the the Fluval freshwater aquarium range have all 3 mediums in their filtration. This will work great so long as you take into consideration how each medium affects the chemistry of the water.

The typical filtration system should come with a carbon insert. The carbon removes CO2 from the aquarium water, along with any other unwanted chemicals. This insert should be replaced every month or two. Aquarium plants love CO2 — they need it to respirate (photosynthesis). When keeping aquarium plants, it’s also a great idea to give them a chemical plant feed. Not only will carbon remove a substantial amount of CO2 from the water, but it will remove any chemical feed as well, so having a carbon insert in your filter is not a great idea if you want to encourage plant growth. 

If your filter has sponge, bio media and carbon inserts, you could replace the carbon insert with more sponge or bio media if you plan to keep live plants. When removing the carbon from the filtration, the plants will counteract this and act as filtration themselves. Aquarium plants are a great natural filter. You can read about this in our plants article.

To give you a real-life example, we bought the Fluval 19L for our current betta, Naan. We wanted to be able to remove the carbon (the chemical medium) from the filter in order to encourage optimal plant growth. This is easily possible with the filter that’s built into the Fluval 19L, which is one of the reasons that we chose it. The built-in filtration is mechanical, bio and chemical. It comes with a sponge insert + 2 inserts: one for a bio sack and the other for a carbon sack. The carbon sack can easily be removed or replaced, which is what we did with ours. Basically the Fluval 19L gave us flexibility. It’s a great ‘works out of the box’ solution for betta keepers. You can remove the carbon if you want plant growth, or you can leave it in if you don’t intend to keep live plants and would prefer to keep the chemical medium.

Another reason that we like the Fluval 19L is because its filter comes with an adjustable output. The output on its lowest setting, combined with the 19L volume of the tank, creates a stress-free living space for a betta. The output nozzle is also adjustable, so it can be angled in a particular direction in order to further control the location and level of the current.

Remember, a betta fish is hardy and can live happily in various water conditions, but some other critters can be quite particular when it comes to an aquarium environment. A betta fish could live happily with just a sponge filter, provided that you replace the insert every month or so and carry out regular water changes. If you plan to keep other inhabitants with your betta, you may need to invest in a filter that can sustain a suitable water condition for the whole ecology of the aquarium. This also brings up the fact that the more critters you have in the aquarium, the more waste there will be, meaning more ammonia, nitrites and nitrates will occur. Your filter needs to be able to handle this.

Scenario 2: adding a filter to an existing aquarium

The other scenario is that your tank does not have a filter built-in, in which case you need to choose one to add to it. Which filter you choose will dictate the amount of control you have over replacing the three filter mediums individually. For example, if you choose a filter that uses an all-in-one cartridge, you may be forced to replace the biological medium at the same time as the chemical medium. This isn’t ideal — we explain why in more detail below. If you choose a filter that houses its media in separate inserts (or has a cartridge that can be modified so that you can replace the mediums at different intervals), you maintain the ability to replace them individually and ultimately this provides more control and flexibility.

There are quite a few great value aquariums on the market that are manufactured specifically with bettas in mind. This means that they come with a filtration unit that’s also great for bettas in terms of size, practicality and filter mediums (you can view some examples aquariums in our best betta tanks article). This may not be the case when buying a separate filter for your betta with the intention of adding it to an existing aquarium. It’s certainly not impossible, but there are a few factors that you need to take into consideration.

For example, if you’re adding a filter to your aquarium, it can be a challenge to find a suitable filtration unit for a water volume that’s less than 15L that won’t create a strong current and that won’t be bulky in the aquarium. This is yet another reason why it’s best for you to keep a betta in an aquarium with a capacity of 15L or more.

Below we have listed some good filters for betta tanks, and we explain how they work in regards to replacing the three different filter mediums. We’ve also listed some of the other pros and cons so that you can choose the appropriate one based on your setup and budget.

Filters that we recommend

Hopefully we’ve explained enough of the theory behind betta filtration that you can now make an informed choice about choosing a new filter. While it’s difficult to simply recommend the best filter for a betta, the two choices that we present below take into account the following:

Reliability, durability – does it do a good job?

Media replacement – are the mediums easy to rinse/replace on an individual basis?

Output – does it create a strong current? does it disturb the surface of the water? If so can it be baffled easily?

Size – will it fit into a 15L aquarium comfortably?

Noise – how much noise does the filter make? Does it become noisy after extended use?

Hagen – AquaClear 20 Power Filter

If you want a quiet filter this is probably as good as it gets (check it out here on Amazon). No filter is completely silent, but the Hagen AquaClear 20 Power Filter does a pretty good job of keeping noise to a minimum.

Another perk of this filtration unit is that it doesn’t use an all-in-one cartridge – you can control and replace each medium individually, which is great for keeping a consistent water quality.


  • Very quiet, produces little noise and will continue to do so if maintained properly. If the aquarium water level is kept consistent the output will make no noise or trickle.
  • Independent medium access. The filtration media can be replaced individually.
  • 3 stage filtration
  • Mechanical media does not need to be replaced (like most cartridge filters) and can simply be rinsed with freshwater and returned.


  • Hang-on filter; it cannot be submerged and may not be compatible with an aquarium with a fitted hood.
  • Unadjustable output – the water output could do with being a bit weaker in order to make it more comfortable for a betta, but depending on the size of your aquarium this may not be a problem. It’s frequently noted by users that it’s easily baffled, so output current can be easily reduced.
  • It’s considerably bulky, but the filter only partially sits in the aquarium, so doesn’t actually affect the water volume. It may however be difficult to fit to a smaller aquarium.

The smallest model is for a 20L aquarium, the largest model is for a 50L aquarium.


Aqueon QuietFlow Internal Filter Mini

As we know Bettas don’t like water disturbance, and a water current that breaks on the surface of the water can even cause them to surface for oxygen less frequently. This is one of the main factors that puts people off getting a filter for a betta, but the Aqueon is great for getting the water conditions just right. It’s one of the only internal mini-filters on the market with an adjustable output rate and position (check it out here on Amazon).

Being a mini-filter, and standing at about 7.8 inches, it does take cartridges, but it’s known for it’s easy adaptability. Shown in the image below, a user has added other manufactured inserts into the filter compartment – rather than having to stick to the Aqueon cartridges. As well as the easy adjustability of the filter media, the rate and direction of water flow on this filter can be adjusted. This is rare to find in mini-filters and is great for betta keeping as you can adjust the filter to create a comfortable current for your betta.

Aqueon QuietFlow Internal Filter Mini


  • Adjustable output height and output current. Can be easily positioned in the aquarium to create the most comfortable conditions for your betta.
  • Easily interchangeable and modifiable.
  • Sits internally, can be added to an aquarium with a fitted hood or lid.
  • A good size – not too bulky.
  • It is aimed at being a silent filter, hence the name ‘quietflow’ and is considerably more quiet compared to other filters on market. But after months of use, some users have commented that the components do start to make more noise, but nothing too unpleasant. If adjusted and positioned correctly, it tends to maintain its quietness.
  • Comes with a bioscrubber insert.
  • The filtration is easily modifiable.


  • It does use a filtration cartridge, which needs to be replaced monthly, but the filtration compartment is basic in a good way – this means that filtration inserts (from other manufacturers) can be inserted independently.
  • Can become noisy depending on the conditions in which the filter is used.
  • As much as the return/output rate can be adjusted, some people have commented that it can still produce quite a strong current, which may or may not affect your betta (depending on the size of the aquarium and how you place it). It can be difficult to baffle, but placing sponge over the nozzle may beneficially reduce the outflow. See our guide on baffling here.

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