Betas (Siamese Fighting Fish) can be kept with other fish. The other fish must be passive and not the types that nip at fins. Betas like shallow, stagnant and warm water, they live in nature in rice patties and puddles along rivers.

The biggest problem with putting them in a community tank is the water movement. They like to sit, not swim constantly. They prefer water of 75 degrees or more.

They can live in a 2-3 gallon tank with no filtration, just water changes every other week and be perfectly fine.

No other Betas in the same tank, of course. Female Betas are ugly, they don't really care to hang out with each other too often.