Do Bettas Really Need Water Filters For Their Aquariums?

You recently bought a betta fish but you’re starting to question if you did everything right and now a particular piece of gear has piqued your interest.

Do you really need a filter for a betta if the pet store sells these fish in small unfiltered jars?

The workers there should be professionals and know best, right?

Unfortunately, this is not always the case.

The short answer to the first question would be “yes” and suppose that you go for one such unit triggers a couple of other considerations.

Did you know that your aquarium’s size plays a role in the choice of the water filtration unit?

If so, which particular water filter suits a 5- or 10-gallon betta tank best?

It does not end there.

The filter too comes with its own set of complications once it is in place.

For instance, what should be the way out for your betta fish if you find the flow rate of the filter current too strong for its massive fins?

There are also different types of filters out there.

Should you go for a sponge or a HOB (Hang-On-Back) unit?

Which is the best brand and model for your setup?

Based on my personal experience and, dare I say, expertise, I am going to provide answers to these questions and some more.

A betta happened to be one of the first fish I kept as a pet about eleven years ago, and so I have something I can share with the beginners in my hobby.

From experience I rudely learned, I can confirm that you’re on the right path when asking yourself these questions. 

So does a betta really need a water filter at all, or it’d be hardy enough to survive without one and everything would be okay?

Let’s get straight to it.

So Do Bettas Really Require Water Filters in their Aquariums?

Most fish require aquarium filtration to live a quality life away from their natural habitat.

However, some people believe this does not apply to bettas because they are supposedly hardy fish.

Here are the factors that determine whether bettas need a filter in their fish tank:

The Betta fish is indeed unique because it can endure hard, low-oxygen conditions in which other fish would quickly fall ill.

But like other animals, bettas excrete wastes that, together with the uneaten foods, pollute the water.

If there is no filter in place to manage the waste by providing mechanical and biological filtration and also aerating the aquarium, the water soon becomes murky and harmful to the betta.

The result could be a feeble life or premature death.

Therefore, a betta fish is no exception and requires a filter installation in its aquarium.

Why it’s Essential to Maintain a Healthy Hygiene in a Betta Tank?

When I just started keeping fish pets, I happily selected this one betta fish after being told it would be easier to maintain, its homely beauty aside.

Everyone kept telling me that bettas are survivors. Okay, bettas can indeed survive in severe conditions.

Nevertheless, some people blow this out of proportion.

As far as they are concerned, a betta is better off without any form of hygiene.

In fact, there is a myth circulating around pet stores that bettas do not need filters — and that is the main reason they sell them in jars!

From where I sit, a betta in a jar is virtually a prisoner hoping for a prison-break.

Here’s the myth:

Unlike many other kinds of fish which rely on their gills, bettas have the ability to suck in oxygen directly from the air. They do this by swimming to the water surface periodically to fetch the oxygen in gulps.

Such fish are called Anabantoids and posses a lung-like organ called labyrinth.

As a pet, bettas use the same adaptation to survive in a bowl or unfiltered aquarium.

For this supposed reason, they are thought to not need a filter (at least if we follow this line of thought). 

And here’s a fact:

The fact that a betta fish can survive in hell should not mean he wants his home to be hell.

For it to thrive and look more attractive, it needs to live in an accommodative ecosystem with pure air and fresh food.

Some well-meaning but uneducated pet lovers also buy into this survivor-myth hence also neglect to take care of their bettas, keeping them in small unfiltered tanks.

They also do not change the water regularly to the point it develops a pungent smell.

However, this is not the newcomer’s fault as they weren’t given better advice in the pet store.

Plus in small fish tanks, the water gets contaminated very quickly.

There are helpful bacteria that establish their colony and dwell in the filter’s media. The colony is called a biofilter.

Perhaps, this is the most important role an aquarium filter plays.

These nitrifying bacteria neutralize the betta’s wastes by converting them to non-lethal organic compounds. Said wastes would otherwise release toxic ammonia in the aquarium water which quickly builds up to lethal levels.

In smaller tanks where water volume is limited, it’s absolutely crucial to provide as much bed for beneficial bacteria as possible, because the harmful chemicals can pollute the water in a matter of hours if there’s not enough of that. These bacteria mainly inhabit surfaces and the porous media in a filter provides plenty of that.

Allowing violent fluctuations in dangerous ammonia, produced by the degrading of fish waste, uneaten food or rotting plant matter, is the most common mistake an entry-level fishkeeper can make.

This is often the cause of a slow and painful end to a betta’s life.

Without a filter, this symbiotic relationship hardly exist; the betta has to face the toxic by-products on his own.

Over time, such neglected bettas lose their glow and vitality.

They become mostly motionless, dull, sickly, and prefer to lie on the bottom much of the time.

It is also at this stage that their fins and tails start to deteriorate. A rotting fin or tail is a telltale; it is an indication that all is not well in the aquarium ecosystem.

As I have said, I learned it the hard way.

The way out of this murky future is a water filtering system to purify the betta’s fish tank.

How Fish Tank Size Impacts the Choice Of An Aquarium Filter?

Perhaps, now is the time for me to mention that if your betta’s tank is anything under 3 gallons you should consider changing it to something bigger immediately.

Tiny tanks and bowls do not provide bettas with a healthy living space.

The fact that such-sized aquariums do not allow for adequate filtration greatly contributes to that.

If you’re still researching or you already have a fish tank that’s too small for your betta, I can help.

I did a super detailed post on the best aquarium kits for betta fish (which all include a built-in filter by the way) and it took me a whole week to put together.

Visit the link if that’s your case.

Anyway, because a small aquarium already has limited space inside, fitting it with a submersible filter could complicate life for your betta fish.

On the other hand, a powerful, submersible filter needs a giant aquarium that can absorb the currents.

This implies that a hang-on-back (HOB) unit would be a better option as a gentle water filter. It will provide more swimming space for your fish pet while keeping the overall aesthetics of the aquarium.

Bettas are famous for their large and beautiful fins which makes it necessary, to consider a filter with an adjustable flow rate, however.

In other words, in a small fish tank with the size of 5 or fewer gallons a HOB filter may not be an adequate option. For these small betta aquariums, a fitting solution would probably be a sponge water filter that’s not bulky in size.

The betta fish, in other words, do not want high flow as much as they do not wish for an unfiltered habitat.

As the caretaker, it behooves you to strike the right balance.

Can The Filter Current Prove To Be Too Strong For a Betta?

This is how the filter current can prove to be too strong for a betta: 

If the filter current strength is more than a betta fish can move against with his large fins, he soon gets tired and stressed.

He may then find it extremely hard to swim around and has to hide or helplessly lay at the bottom instead.

Strong current can actually damage the betta’s fins. With unfit fins, the betta can easily drown. So while a strong filter may not directly kill betta fish, it can gradually facilitate death through exhaustion.

The bottom-line cannot be overemphasized: 

Whichever aquarium filter you go for, it should not have a high current output that interferes with the betta’s mobility.

The solution to this is having an aquarium filter that has an adjustable valve which you can use to control the flow.

Otherwise, you could find your dear betta deadly exhausted and sucked into the filter inlet tube.

Choosing the Best Filtration Unit for Your Betta Buddy According To Gallon Count

As I have already explained, smaller aquariums need less powerful betta fish filters.

But how do you decide which filtration unit will do for your particular aquarium?

Here are the best water filters for a betta according to the fish tank’s gallons count:

Filtration For a 3 Gallon Betta Fish Tank

As a best option for a 3-gallon fish tank with a betta in it, the XINYOU XY-2835 Fish Aquarium Mini Cylinder is appropriate mainly because it does not produce much current.

It guarantees your betta fish both a calm and clean water in that limited space. With water always clean, the betta will always look radiant and active.

The 3/4 inches filter is primarily a sponge. The sponge is however too soft to harm your betta’s tender fins and there’s no noticeable filter current.

The unit is also easy to clean; you just squeeze some of the old water out then clean the uptake tube.

Again, it is easy to set up and so suits a beginner. Don’t forget to use dechlorinated water when washing the filter, to not kill the beneficial bacteria that are residing in it.

Filtration Unit For a 5 Gallon Betta Fish Tank

For a 5- or 5.5-gallon tank, you should still go for XINYOU XY-2835 Fish Aquarium Mini Cylinder.

In a fish tank of this size, it is even quieter but still as effective in filtering the water.

It keeps the water crystal clear, enabling the bettas to enjoy swimming back and forth through the gentle bubbles. 

I really think this is the best water filter for a small betta fish tank, overall.

The unit’s bottom is fitted with some weight to keep it on the tank bottom.

However, if the filter acts like it is going to float, give it a squeeze while it is submerged to fix the problem.

Filtration Unit For a 10 Gallon Betta Fish Tank

For a 10-gallon betta fish tank, an adequate filtration system choice would be the Marina S10 Power Filter.

I’m recommending this product as the best choice because it has a comparatively slim, compact, and elegant design that not only ensures it takes less space but also provides aesthetic benefits to your aquarium.

It is easy to set up and even easier to customize the media into it.

The best news for your betta is the cool adjustable flow rate that it provides.

It operates quietly, once its motor sinks in the tank water. The betta can fearlessly swim through the gentle current.

There is a sponge over the intake to prevent your betta’s fins from getting sucked in, just in case.

I’m positive that the Marina S10 really works to your pet fish’s best interest.

Filtration Unit For a 20 Gallon Betta Fish Tank

The AquaClear 30 Power Filter is one filtration unit that efficiently works for a 20-gallon betta fish tank.

First, its adjustable flow rate is a huge plus for the betta.

Secondly, its filtration volume goes up to 7 times larger than other similar filters.

This is due to its multi-stage filtration system that efficiently provides a combination of biological and chemical filtration.

This ensures the water is super clean all the time, making this filter among the best choices for a betta aquarium of this size.

Moreover, all these processes occur without turbulence, for the benefit of your betta’s fins.

The AquaClear 30 also establishes the symbiotic relationship between the fish and the beneficial bacteria that live on the filter’s bed.

It is also easy to clean and you do not have to remove the whole unit from the tank when doing so.


With all this said, the ball is now in your court. 

Evidently, bettas do need a filter for more than one reason, including a healthy long life.

It’s really best to provide yours with one for both your pet’s sake and yours.

Bettas look prettier when they live in an environment that guarantees good health because that promotes a more pronounced coloration.

They may endure hardship, but this would eventually take its toll on their well-being.

Be sure to drop me a comment if you need more guidance on the subject.

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