Do Betta Fish Need a Filter?

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Like many people, I used to keep Betta fish in a small bowl without using any equipment. The fish store always displayed them in a jar. That’s why I assumed they should be kept that way.  

However, since then, I learned that they need at least a 2.5 gallons tank to live in. Not only do they need more room, but they also need to have clean water!

This leads us to the question. Do Betta fish need a filter? The short answer is YES, your betta fish does need a filter. Unless of course, you enjoy doing multiple water changes every single week. I know I don’t.

Do Betta Fish Need a Filter?

Fish, like other forms of life, produce waste products. In an enclosed environment, such as a fish tank, waste products have to be removed for the health of the inhabitants. Filters remove these waste products from the aquarium environment.

By keeping a Betta fish in a small bowl without filtration you’re actually shortening the life of your pet. They are also unhappy and visibly less active. I’ve never been able to keep any of my siamese fighting fish for long in these environments.

Now I know better. They can survive low oxygen environments due to their labyrinth organ which allows them to breathe air. But this is no excuse to neglect them. Water quality is important to betta, just like any other fish

The Benefits of filtration

betta fish in an aquarium with plants and pebbles

As I already have stated, I have kept fish bowls without filtration in the past. However, using a filter offers several benefits in your betta tank.

  1. It’s easy to overfeed betta fish as they won’t be able to eat every morsel of food that you throw into the tank. This means cleaning the tank more often, in addition to using bottom feeders to help with the excess food at the bottom of the tank. Having a filter decreases the number of clean-ups and water changes that become necessary without one.
  2. Fish emit chemical wastes, such as ammonia into their surroundings. Changing water regularly helps, but the most efficient way to get rid of these chemical wastes is an efficient biofilter.
  3. Better hygiene. A dirty fish tank can give off an unpleasant odor from ammonia and other impurities. This can affect your environment as well as the fish tank. Filtration will reduce this problem.
  4. Filtration will result in a cleaner looking tank. This adds to the beauty of a well set-up aquarium.
  5. You won’t have to clean the tank or change the water as often. Believe me when I tell you that changing the water in a large tank can be a big deal. You may have to change between 10 to 15 percent of the water depending on the size of the tank. You also need to have clean, treated water standing by to refill the tank.

considerations when choosing a betta fish filter

When choosing a filter for your betta, you should consider the following:

  • In the wild, betta fish live in areas that contain slow-moving water. Rice paddies, swamps, ponds, and slow-moving streams. They’re not very strong swimmers because of this. You’ll have to take this into consideration when you purchase a filter. Make sure the water flow isn’t too powerful.
  • Water quality should also be a consideration for your tank. In a small tank without a filter, water quality can quickly deteriorate. If you’re a busy person, you won’t have a lot of time to clean your tank. Filtration will minimize the number of water changes necessary.
  • If your tank is under 3 gallons, a filter won’t be ideal for a tank that size.

Betta Fish Filter Recommendations

Now that I’ve answered the initial question, “do betta fish need a filter?”, here are a few recommendations.

The Hygger aquarium double sponge filter

Sponge filters are some of the best filters for slow swimming fish, such as bettas. Not only this, but they are one of the simplest filters available. This filter is available in a variety of sizes up to 55 gallons, so make sure to select the proper one for your tank. This one is suited to tanks ranging from 10 – 40 gallons and comes with two sponges, a filter body, bio balls, and 2 suction cups. There is also a smaller 0.5 – 5-gallon single sponge version, but it does not include the bio-balls.

However, it doesn’t come with an aquarium air pump. This will have to be purchased separately but they are generally affordable. The filter itself has no moving parts and the airflow from the air pump is what forces the water through the filter. I use the Tetra Whisper Air Pump personally. Also, don’t forget some airline tubing as well.

The water exit nozzle can be adjusted in different directions and will certainly help minimize water current for your betta fish. It also runs super silent which is a huge plus for me!


  • Very high turnover rate (GPH: tank volume 5:1 to 3:1 ratio)
  • Specifically designed compartments to avoid water bypass
  • Spacious, well-separated media compartments with Tote Handles for easy maintenance
  • Included media covers all three filtration stages


  • Not the quietest filter
  • Large even for a canister filter

Aqueon Quietflow Internal power filter

The Aqueon Quietflow filter is a fully submersible power filter. It’s available in 3, 10, 20, and 40-gallon capacities. It’s designed for three-stage filtration including a dense foam to remove particles, activated carbon to remove discoloration, toxins and odors, and a Biogrid to remove ammonia and nitrates.

It’s an all-rounder when it comes to filtration. It combines mechanical, biological and chemical filtration. While it does a great job cleaning your aquarium the flow may be a bit much for your betta.

If you have a 5-gallon tank you are stuck with the choice of choosing between the 3 and the 10-gallon model. The 3-gallon will create less current but may not filter as well. Using a 10-gallon filter will ensure you have a clean tank but the current may be too much for a betta.


  • Very high turnover rate (GPH: tank volume 5:1 to 3:1 ratio)
  • Specifically designed compartments to avoid water bypass
  • Spacious, well-separated media compartments with Tote Handles for easy maintenance
  • Included media covers all three filtration stages


  • Not the quietest filter
  • Large even for a canister filter

Penn Plax Cascade Hang-on Aquarium Filter

This filter is the tried and true HOB or “hang on back” filter design. One of the things I appreciate about these filters is the fact that they do not take up any room in your fish tank. This model is designed for a 7-gallon aquarium but they also have other models for larger ones. It comes with double-sided media that contain activated charcoal and poly-fiber floss. 

It comes with double-sided media that contain activated charcoal and poly-fiber floss. It will reduce toxins and chemicals, bad smells and floating particles from your fish tank. This filter doesn’t provide for effective biological filtration. But this can be aided by adding a pre-filter on the inlet or sponge filter foam to the housing.

One of the advantages of this filter over my other two recommendations is the adjustable flow rate. This is controlled by turning the nob on the top of the filter. This will help you set a comfortable flow for your betta fish.


  • Very high turnover rate (GPH: tank volume 5:1 to 3:1 ratio)
  • Specifically designed compartments to avoid water bypass
  • Spacious, well-separated media compartments with Tote Handles for easy maintenance
  • Included media covers all three filtration stages


  • Not the quietest filter
  • Large even for a canister filter

Which is the best betta fish filter?

Each of these filters is affordable, simple and effective. But my personal pick for filtration would have to be the Hygger Aquarium double sponge filter. It has very minimal maintenance requirements and it’s the simplest of the trio. I do like simple things a lot.

How do Aquarium filters work?

We now know that an aquarium filter is a must-have if you want the best for your betta fish. But how do aquarium filters work in a betta fish tank? What’s with the replaceable pads and cartridges? Are all filters basically the same?

Read on and I will answer these questions and more.

The Different Types of Filtration

Filters work by removing contaminants from the water. These contaminants can be solid, chemical or mineral in nature. Because there are 3 different types of contaminants there are 3 different types of filtration found in a good filter. These filtration types are mechanical, biological and chemical.

Mechanical Filtration

Mechanical filtration works by removing solid floating particles from the fish tank water. Uneaten food, fish excretion and other solid particles are just some of the items that the filter takes out of the water

Most enthusiasts would’ve used this type of filter when they just started out. They use either pads, sponge, or filter wool as the medium in the filter. They may either be coarse or fine, depending on the level of filtration needed. Finer media will filter out smaller particles than a coarser filter.

Types of mechanical filters would include :

  • Pads or sponges which are included in canister filters as well as some power filters.
  • Floss or filter wool which was used in the box filters. This is not commonly used these days. If you’ve been keeping fish as long as I have, you would certainly have used these in your tank. You’ll also remember that it’s not a pretty sight when it needs changing.
  • Combo cartridges are used to combine chemical and mechanical filtration into one cartridge. Some of them can be opened to change the cartridge, while others must be replaced after a while.

Biological Filtration

With biological filtration, good bacteria transform ammonia and nitrite into the less toxic nitrate. Fish waste is, therefore, turned into nitrate by these beneficial bacteria. This process is called the nitrogen cycle. Filter media for biological filtration is designed to accommodate a large amount of beneficial bacteria. This design usually incorporates lots of porous surface area to give good bacteria plenty of room to grow.

Types of biological filtration media include :

black bio balls for biological filtration in an aquarium filter
  • Ceramic rings which accommodate both denitrifying and nitrifying bacteria. 
  • Ceramic balls which will also accommodate both types of bacteria. They also have a large surface area for their size.
  • Bio balls are another type of biological filter. They are, however, only useful for nitrifying bacteria.
  • Moving Bed filter media. This is used only for nitrifying bacteria. The idea with this type of filtration is that only the strong survive. Each part of this media constantly crashes into its other parts. Only the strongest bacteria will be able to hold on to the surface and filter your tank.

Washing your biological media in tap water will remove any bacteria living on it, so avoid cleaning it this way.

Chemical Filtration

Chemical filtration, as the name suggests, removes chemicals from your fish tank. Contrary to what you might think, chemical filtration is one of the most important forms of filtration you can have in your tank.

Some forms of chemicals can be silent killers of your fish. This is because you can’t actually see some forms of pollutants. You’ll be going along thinking everything is OK since your tank is looking quite clear and pretty. Then, suddenly, your fish start dying off.

Heavy metals and other soluble compounds can slowly poison your fish over time. Chemical filtration will remove these, as well as other forms of chemicals in your tank.

Keep in mind though, that pollutants can be a sign of a problem in your tank which needs to be addressed as soon as possible.

Types of chemical filtration include

  • Activated carbon is the most common chemical filter media. It is known for removing organic pollutants that are missed by biological and mechanical filtration. It’s often used in conjunction with mechanical filters. The carbon is composed of tiny pores that trap and remove pollutants from your fish tank water.
  • Ion Exchange is a process that attracts specific molecules to attach to a medium. This means it takes in ammonia, nitrate and or dissolved organics in exchange for sodium. The media used for this process is Zeolite or synthetic resins. It may also be used along with activated carbon to more completely remove a wider array of chemicals.

Changing out your chemical filter is a must since they do lose effectiveness after a couple of months.

Types of Aquarium Filters

There are a wide variety of aquarium filters in use today. Some of the more popular filters include sponge, canister, power, undergravel, and fluidized bed filters.

Sponge Filters

A sponge filter is an affordable basic filter consisting of:

  • An air pump, which sits outside of the tank.
  • A sponge filter, which sits inside of the tank.
  • An airline that connects the filter and the pump.

The pump pushes air through the tubing into the filter. Bubbles rise from the sponge, creating a vacuum that draws in water. The sponge works as a mechanical filter, drawing solid particles into the sponge. It also works as a biological filter, attracting beneficial bacteria that will grow on the sponge.

Not only do these filters clean the water, they also provide oxygen to the water. These are also one of the best filters for betta fish because they create very little water current. They also work quite well in a small aquarium.

Canister filters

A canister filter is a plastic container kept outside of the tank. It draws in water through tubing using an electric pump. The filter contains different types of filtration media through which water is drawn before exiting through another tube back into the tank.

While they have many benefits they are generally used for tanks over 20 gallons. They are also expensive. For these reasons, I would not recommend this filter type for betta fish.

Power Filters

Power filters also are known as HOB or hang on back filters and are one of the most common filters available. They are also a great choice for a betta fish filter.

Power filters are impeller powered filters than hang on the back of your fist tank. They work by removing water from your tank through tubing into a housing containing various types of filtration media. The water then cascades out of the filter and back into the tank.

Power filters are easier to maintain and cheaper than a canister filter. Smaller ones can service a 5-10 gallon tank, while larger ones can be used for much larger tanks. They’re also relatively affordable.

They, however, can be quite noisy to use. As the water level gets lower the water coming out of the filter falls farther creating more noise. I have two in my bedroom and often get up in the middle of the night to top of the water level because of the noise.

Fluidized bed filters

A fluidized bed filter is a cylinder or canister that hangs off the back of your tank. They’re connected to a pump that pushes water through the filter. The filter contains sand that acts like a fluid (fluidized) when water passes through. The sand, then, works as a large surface for denitrification bacteria.

Undergravel Filter

This is one of the older types of filters in use. I’ve used this in my tank and found it to be quite effective. However, your plants won’t do well if you have one of these types of filters.

Undergravel filters consist of a large porous plate that is placed on the bottom of your tank under the sand. It has a lift tube at each corner at the rear of the tank. Water is drawn up the lift tube by a motor or powerhead at the top. This draws water from under the plate which, in turn, draws water through the sand. This creates a healthy environment for denitrifying bacteria that live in the sand.

There are few if any commercial models of this filter type currently available. They are also a bit more involved to set up compared to a HOB or sponge filter. Therefore, this probably isn’t the best filter for your betta fish tank.

Final Thoughts

I hope that this article has convinced you that betta fish do need a filter for optimal health and longevity. I also hope that you learned a lot about filter basics as well as some good filters to use in your betta tank.

Feel free to comment or asks questions below!