Hard to say sometimes you never know what a fish is going to. However, you shouldn't mix bettas with normal fish. Bettas will try to hurt and attack the smaller fish. Also, you should keep a betta in an aquarium between 1-2 gallons of water. Anything larger would be bad for a betta because there fins start to rip and tear in a large tank and anything smaller than 10 would be too small for a group of minnows.