There are a few more information pieceshat we should have information to depict what type of freshwater fish that could inhabit this tank properly with the details
-Tank Dimensions?
-Ph, and Hardness?
-Is your Betta relatively peaceful?
-Substrate?
-Tank temperature?
-Is the tank relatively mature regarding age, and whether or not it's cycled?
-Is it planted?
-Filteration?
-What those if fish are you aiming for?
-Small colorful schooling fish, small catfish, bottom dwellers?