Last update: November 4, 2022

Do Betta Fish Need A Filter?

When it comes to keeping betta fish, there are many different opinions on the best way to do things. One of the big questions people have is whether they need to use a filter in their betta fish tank.

The answer to this question is not simple, as there are pros and cons to using a filter to clean aquarium water. One of the most significant benefits of using a filter is that it helps to keep aquarium water clean.

A filter can help maintain water quality through regular water circulation and filtration. But, there are also some drawbacks to using a filter in a betta fish tank. Filters can be expensive, and they also need regular maintenance.

Also, some betta fish prefer not to have a filter in their tank, as it can create a lot of water movement and noise.

Ultimately, whether to use a filter in a betta fish tank is up to the individual fish keeper. There is no right or wrong answer, as each situation is unique.

Betta Fish Habitats Without Filters

Betta Fish Habitats Without Filters

Rearing betta fish in a habitat without a filter has drawbacks worth considering. But one of the most significant advantages of not using a filter is that it is cheaper and easier to maintain.

Betta fish kept in filtered tanks often become stressed. This stress is due to constant water movement and noise. As a result, they may be more likely to become sick or exhibit other health problems.

Injuries are also prone to occur in betta fish kept in filtered tanks. The constant water movement can suck them into the filter equipment. The sucking mechanism can lead to severe injuries.

Finally, betta fish kept in filtered tanks often have a shorter lifespan than those observed in unfiltered tanks.

On the other hand, there are significant disadvantages to not using a filter. Without a filter, the aquarium water quality can quickly deteriorate. There is no way to remove debris and waste from the water regularly.

As a result, the water can become polluted and harmful to betta fish due to ammonia build-up.

Caring For Betta Fish Without Filter

Betta fish in the wild live with natural filtration in rice paddies and the Amazon. This is because live plants help with the nitrogen cycle.

Natural environmental water conditions are best. Water temperature and oxygen saturation are at their best because of biological filtration.

Caring for betta fish in an aquarium without a filtration system can be difficult. Before going without a filter, there are a few things to consider first. You need to consider the number of fish to keep in the tank and the size of the tank.

The higher the number of fish, the faster the waste build-up. Hence the water quality will deteriorate quicker. This means the tank needs more regular water changes.

The smallest recommended betta fish tank without an aquarium filter is five gallons per fish. Despite this, it’s not recommended to go filter-less. That is unless you are willing to do frequent, significant water changes.

Going lower than five gallons without a filter, you will need to do at least 50% water changes every other week. This is especially needed if your tank is on the smaller side.

Adding more fish to the tank will need significant adjustments to prevent overcrowding. If not addressed early, overcrowding leads to stress, poor quality of life, and eventual death.

It is best to avoid constant water changes since it interferes with beneficial bacteria.

Regularly test the water with test strips to ensure good water quality. Ammonia and nitrite should be at 0 ppm, and nitrate should be below 20 ppm.

Betta Fish Habitats With Filtered Tanks

Betta Fish Habitats With Filtered Tanks

The best place to start is to get a tank suited for betta fish. The minimum recommended tank size for keeping betta fish with a filter is 2.5 gallons.

Betta tanks that are 2.5 gallons and up can come with an included filter. But, it is still essential to do your research to ensure the filter is appropriate for betta fish.

If your tank does not come with a filter, there are many filters to choose from in the market.

It is vital to select a filter that is the appropriate size for your tank. Also, you will need to choose a filter with adjustable flow rates. A filter with a higher flow rate than your betta fish can handle is dangerous.

This danger is because betta fish are not able to swim against strong currents. As a result, they can become stressed out and more susceptible to illness or, even worse, death.

But, choosing a small filter has its problems, too. A smaller filter has to work harder to filter more water. Attempts to filter more water than it can hold will result in a low-filtration quality. This will then provide a low-quality environment for the betta fish. The fish cannot thrive in this type of environment.

Benefits of Betta Tanks with Filters

One of the benefits of using a filter is that it helps to keep the water clean and clear. Also, it eliminates the need for performing frequent water changes.

A filter will remove fish waste and uneaten food from the water. This removal helps to clean water and maintain a healthy ecosystem. Excess build-up of solid organic matter will cause eventual rot and a drop in water quality.

It is impossible to keep any other fish with betta fish without a filter. This is because ammonia build-up can become toxic to tank mates like feeder guppies.

Another benefit of using a filter is that it helps to create a more stable environment for betta fish. This is because the filter helps to remove toxins and waste from the water regularly. 

A filtration system will boost water oxygenation and help to maintain a healthy pH level in tank water. This creates a comfortable habitat for the betta fish. And as a result, they are less likely to become stressed.

In addition, a filter also provides a place for beneficial bacteria to grow. These bacteria help to convert ammonia into nitrites and then into nitrates.

Nitrates are much less harmful to betta fish than ammonia and nitrites. As a result, using a filter can help create a safer environment for betta fish.

Best Betta Filters

best betta filters to choose from

Choosing the best filter will depend on the size of your water tank and the number of fish you intend to keep. There are several best betta filters to choose from, including:

  • Hang-on-back filters
  • Canister filters
  • Power filters
  • Sponger filter
  • Corner filters
  • Undergravel filters

Hang-On-Back Filters

Hang-on-back (HOB) filters are an excellent option for betta fish tanks of all sizes. HOB filters hang on the back of the aquarium and are easy to install and maintain.

HOB filters are also relatively inexpensive. This price makes them an excellent choice for budget-conscious betta fish owners. Also, most HOB filters come with adjustable flow settings. So you can customize the level of filtration to meet your betta’s needs.

Many HOB filters include activated carbon pads that help remove impurities and improve water clarity.

When shopping for a HOB filter, choose one sized appropriately for your aquarium.

Canister Filters

Canister filter outside aquarium

Canister filters are aquarium filters that use a canister to hold the filter media. Canisters are usually located outside aquariums. Water pumps into the canisters from the aquarium. The water then passes through the filter media.

Canister filters are often used in larger aquariums. They provide more thorough filtration than other types of aquarium filters.

Canisters route water to other aquarium equipment, such as UV sterilizers or protein skimmers. Canister filters are also pretty easy to maintain and provide excellent filtration for your betta fish tank.

But, one should be cautious with canister filters as they create a lot of turbulence. This turbulence can hurt your betta fish.

Power Filters

Power filters use an electric pump to circulate water through a filter media. Power filters are often used in aquariums and ponds but can also work in other water systems.

Many different brands and models of power filters on the market work in similar ways. The power filter draws water into the intake tube. The drawn water then passes through a mechanical filter media such as a sponge or charcoal.

The filtered water is then pumped back into the aquarium or pond. Power filters effectively remove debris and contaminants from water. This filtration helps to keep your betta fish healthy and clean.

Sponge Filter

Sponge Filter

Sponge filters are an excellent option for betta fish tanks and small aquariums. They are easy to set up and maintain, effectively filtering out debris and waste.

Sponge filters work by drawing water through a filter sponge, which traps particles of dirt and debris. The water is then returned to the tank and cleaned of impurities and harmful chemicals.

Sponge filters are very affordable, and they can be easily made at home with basic materials. They are also very gentle on betta fish.

Corner Filters

Corner filters are a type of aquarium filter designed to fit into the corner of a betta fish tank. They are usually small and compact, making them suitable for smaller tanks.

Corner filters can be either internal or external. And they typically come with adjustable flow rates. Some corner filters also have built-in heaters, which can benefit betta fish.

Overall, corner filters are a good option for betta fish tanks, and they can help to keep the water clean and clear.

Undergravel Filters

Undergravel Circulation Filtar

Many betta fish tank owners use an under-gravel filter in their aquarium. The filters stay installed at the bottom of the tank, under the gravel.

Water flows through the gravel, then through the filter, and returns to the tank. Undergravel filters are a great way to keep your betta fish tank clean and clear.

They are easy to set up and maintain, and they provide a good level of filtration for betta fish tanks.


Whether or not to have a filtration system depends on a few different factors – namely, the size of your betta fish tank and the number of fish you intend to keep. If you have a small tank with only a few fish, you may not need a filter.

On the other hand, a filter is essential if you have a large tank or intend to keep a lot of fish.

No matter what size tank you have, regular water changes are essential to maintain the health of your betta fish.

Filters can help keep your tank clean and clear and provide a source of aeration for your betta fish.

When choosing a filter for your betta fish tank, choose an appropriate size for your tank with an adjustable flow.

Avoid tanks smaller than 2.5 gallons like fishbowls. These are too small to accommodate a healthy environment for your fish.

Ian Sterling

Ian Sterling, founder of, began his aquarium journey over 30 years ago, driven by a deep fascination for fish and their diverse personalities. His website,, is dedicated to making fishkeeping accessible and enjoyable, offering beginner-friendly guidance, expert insights, and a community for aquarists to connect and share experiences.

Comments (2)

Wow, what a thorough breakdown of the debate on using filters for betta fish tanks! It’s fascinating to see the pros and cons weighed so carefully. While filters undoubtedly help maintain water quality and reduce the need for constant water changes, it’s eye-opening to learn about the potential stress and injuries they can cause to bettas. The section on natural habitats versus aquarium setups was particularly enlightening, highlighting the importance of mimicking natural conditions for these beautiful fish. Thanks for sharing such valuable insights! Readers can also visit Animal Quick

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