It looks like 3 corys would be good with the betta in that 10 gallon tank.
Well Known Member
5 to 10 years
Be careful though - corys are schooling species! I'd say use shrimp of some kind in stead of corys. With corys - you need at least 6 of each kind.
Shrimp are often seen as food by Bettas and Corys can be happily kept in numbers as small as 2-3, although they're happier with 6 or more. Corys are pretty much the most compatible tankmate available for Bettas.