Do Betta Fish Need a Water Filter?

Bettas are usually seen in aquariums without a filter. In stores, they are sometimes kept in tiny glasses of water. So do betta fish really need a water filter?

A filter is not a must for a Betta to thrive. However, it would help a lot in keeping the water quality high, removing the debris and keeping your pet fish happy and healthy. So even though it’s not a must, a filter is recommended for a Betta tank.

The biggest challenge with Betta fish and adding a filter to their tank is the fact that the aquarium itself is usually smaller. This makes it very difficult to actually have room for the filter itself.

Even though ideally, one Betta would have at least 5 gallons of water (19 liters), most are kept in much smaller bowls, as little as 67 oz (2 liter). In such a small bowl, it’s impossible to add a filter.

Ideally, you should move your pet fish in a much larger bowl or fish tank, so it enjoys life better. But if you can’t… will your Betta survive without a water filter?

Yes, it will. But you will need to perform water changes and tank maintenance a lot more often than you would if you had a filter installed in the tank in order to keep water quality under control.

How often should you clean a Betta fish tank without a filter?

betta without a water filter

Depending on the actual size of the tank, you will have to perform maintenance and partial water changes frequently. You should change the water one time per week with smaller tanks and once every two weeks if the aquarium is larger.

These things are not really set in stone, as you have a lot of other things to take into consideration.

Things like the size of the tank, if it is heavily planted or not and how many other fish or animals are living in the tank – they all matter.

The more debris and waste is produced, and the fewer plants you have, the more often you will have to change the water.

No matter how often or rarely you do it, though, always perform a partial water change in your Betta tank.

This means that you should only remove 30% (or a maximum of 50%) of the water in the tank, otherwise you will destroy the water balance. Smaller tanks and bowls are more difficult to maintain simply because there is less water and the balance can be easily upset.

Betta fish and filters

If you read this blog regularly, you know that I love self-sustaining water ecosystems and try to build my tanks to require as little maintenance and interference from my side as possible.

do betta fish need a water filter

I did manage to maintain a 5 gallon Betta tank without a filter for years, until the fish died of old age. But there are challenges and definitely this isn’t beginner friendly.

Related reading: Funny & cool names for your Betta.

My Betta fish tank setup without a filter included a heater, a ton of plants (really a ton – it was a jungle in there!) and several Red Cherry shrimp and Zebra snails.

I do believe that the Betta kept the shrimp population under control as they never overpopulated the setup, but he also never ate them all.

In my case, the biggest challenge was not keeping the water parameters in check even though I only performed partial water changes on a monthly basis since the tank was heavily planted.

However, since there was no water movement whatsoever, there was some initial bacterial bloom on top of the water and once solved, there were always bits of white film on top of the water.

Keeping the water clean and clear, with normal parameters in a tank without a filter is really difficult, even if there’s just one Betta living there. And there’s really no point in trying it, especially as for 5 gallon tanks, there are already options for smaller filters to help you a lot.

I would go as far as saying that only tanks with plants-only can really thrive easily without some sort of filtration. Or experiments like sealed jarrariums, where you never change the water, but keep everything underpopulated in the first place.

Otherwise, always choose a filter. It will make your life a lot easier and even though it might seem like it’s going to require more maintenance, it’s usually the other way around.

With a filter installed in your Betta’s fish tank, you will have to change the water less often, but you will also avoid other problems caused by the water being still – such as algae bloom, bacterial bloom or that nasty film on top of the water.


You don’t really need a water filter for your Betta fish to do well. But if you go without a filter, prepare for more challenges in keeping your water quality under control, as well as regular water changes and more maintenance of the tank itself to keep your Betta happy.

The easiest option remains that of installing a filter that’s appropriate to the size of your fish tank. Maybe go for a larger one if it’s too small.

Even though Bettas are kept in tiny tanks, they won’t really feel good cramped like that and would rather have some extra space to stretch their fins.

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