"Our small daughter was given a 5 gal aquarium for Christmas this year by a relative. Said relative then took her to Petsmart and bought her a male Betta. We are new to all this but willing to learn for her. We'd hoped initially to be able to add other fish in with the Beta. We've asked several store people if that's possible and, if so, what kinds of fish would work. We've gotten many different answers, mostly conflicting ones(!). Can someone definitively guide us as to whether or not other fish are compatible or if we need to return the Betta and go with a different mix??"