Can Betta Fish Live in an Unfiltered Aquarium?

betta fish it is important to ensure that the aquarium setup be a replica of your underwater ecosystem. This means that there is a need to balance all the various elements available in nature to provide the perfect and thriving environment for your fish.

THE filtering an aquarium it is a very important part of that delicate balance that helps everything to thrive and grow. Therefore, having a filter is crucial for the health and well-being of our aquatic companions.

the betta fish can even live without a filter in an aquarium as long as you make some adjustments to the water frequently and monitor key parameters (ammonia, nitrite and nitrate). Below, understand a little more about this subject!

Why do my fish stay on the surface…

Yes, betta fish can live in an unfiltered aquarium., but that doesn’t mean he’ll be completely fine. It is interesting that you understand that you will hardly find a fish in the wild that can survive for longer periods in water that has not been naturally filtered.

The purpose of the filter is to keep the clean aquarium and replicate the same conditions and parameters of their natural habitat.

What happens if I leave the betta in an unfiltered aquarium?

Without a filter, numerous harmful bacteria begin to breed in the aquarium. Many of the products from these bacteria can dilute as you perform partial water changes but they will still remain a threat to your fish.

Dirty water itself can cause stress on your betta fish weakening your immune system and making you more vulnerable to illnesses. In addition water quality is greatly impaired in small aquariums and without filters. The smaller the volume of water, the faster it will deteriorate. Unconsumed feces and feed result in the accumulation of ammonia, nitrite and nitrate. These substances, in large quantities, stress the bettas and leave them sick. That’s why it’s quite common bettas with gnawed fins in such environments.

A betta fish that is living in an unfiltered aquarium will live for a shorter time. In addition, you will have to perform partial water changes much more often to keep it in good quality. However, be aware that repeatedly changing the water can also stress the fish.

An aquarium that does not have a filter will have a difficult time having a strong growth of beneficial bacteria. At beneficial bacteria are essential to gain control over the main water parameters. Any changes to these parameters will cause the aquarium to become an unsustainable environment for betta fish.

Finally, not having a filter also means that the aquarium water will not be oxygenated, causing it to become stagnant. This will not only make your betta look sick but will also leave the bad smelling water.

Why are filters so important for a betta fish aquarium?

Over time, the aquarium begins to accumulate debris from many different sources. This can include decaying organic matter, harmful bacteria, rotting feed, chemicals and feces.

For your betta’s well-being, all these harmful elements need to be removed from the aquarium from time to time. A filter is able to eliminate these harmful substances by sucking the water and passing it through a rigorous filtering process. (mechanics, chemistry and biological). After going through all these steps, it returns clean to the fish tank.

How do I know if the filter is not suitable for my betta fish?

The easiest way to find out whether or not a filter is suitable for a betta fish is to pay attention to the current formed by the filter.

The water flow through the filter will be too strong for the fish if:

  • The betta is frantically swimming against the current;
  • The betta stays hidden away from the filter, preventing its flow;

If your fish is frantically swimming towards the stream of water or is mostly hiding in a place with a slower flow it is good to check that the flow is not too strong.

If you already have a filter, you don’t necessarily need to buy a new one. You can add some kind of sponge at your inlet to lessen its flow.


To summarize, betta fish can live without a filter, but not for long. Not including a filter makes your fish susceptible to illnesses and illnesses.

If you love your goldfish, try to acquire a filter, but be careful that it is not too potent. Bettas love quiet environments, so you should invest in a filter that makes them comfortable and happy!

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