I have a 30 gallon African Cichlid tank filled with 8 lundu (red topped and zebra) they're all about 2-3 inches right now. There's one that's about 3.5 and he beats on all the fish. Most of them are torn up and one jumped out of the tank and nearly died. if I take him out of the tank the next biggest fish just does the same thing... I'm pretty sure they're mostly females but I'm new to fish and can't be sure. How do i get them to get along better?