Betta fish are reputed as territorial and bad tank mates. The feistiness is, however, mostly targeted to other bettas, rather than other fish species.
In the wild, male bettas engage in territorial disputes, and less-dominant males are often forced to flee. Male bettas can cause injury and even death to each other, which is why you should keep them apart.
Avoid keeping bettas with species that are larger or those with similar fins. Additionally, do not keep bettas with fin nippers like red tail sharks or angelfish.
Some of the ideal betta tank mates are:
Mystery Snail
These peaceful aquatic species will keep your tank clean by eating algae and debris. The snail will quickly retreat to its protective shell if the bettas become aggressive.
The mystery snail does not reproduce asexually, which will help to keep its numbers in check.
Tetras
Many tetras will make good tank mates for your bettas. Small species like the ember and neon tetras will out-swim your betta if it gets aggressive.
Most tetras are shoaling fish, and they will add color to your tank. Some ideal tetras include the diamond tetra, black neon tetra, silvertip tetra, cardinal tetra, and the rummy-nose tetra.
Corys
The Pygmy Corydoras grows to about an inch in length, and it enjoys similar water parameters as the betta fish.
It prefers to roam at the bottom of the tank and will stay away from the upper layers where the betta fish stays.
The cory catfish grows to 1.0 to 2.5 inches, and it will live peacefully with your bettas. Keep the cory catfish in schools of at least four.
Other cory species to consider include the albino cory and the panda cory.
Harlequin Rasbora
If you have a 10-gallon tank or more, consider keeping the harlequin rasbora. It is a shoaling fish that grows to 1.5 inches in length.
This fish co-exists with the betta in the wild, making it a fit tankmate.
African Dwarf Frogs
African dwarf frogs will tolerate similar conditions to those of your bettas. They are also hardy, and they reach 2.5 inches in length.
The fish are quite active, and you will mostly observe them coming to the surface for air. It also sheds and eats its skin every one to two weeks.
Kuhli Loach
The Kuhli loach is active in the evening and at night. It will, therefore, not run into the betta, minimizing the risk for any aggression on the betta’s part.
Other tankmates to consider are the clown plecos, ghost shrimp, nerite snail, and the galaxy rasbora.