I have a smallmouth bass, rock bass, bluegill, black crappie, and a pumpkinseed in my 210. The smallmouth bass and the rock bass own the tank. They chase all the other fish around. The SMB is about 16" and the rock bass is about 7". The bluegill is about 8", the pseed is about 6" and the crappie is about 5". I have some large driftwood in the middle but, but only some small pieces on the sides. Do I maybe need to add more places to hide so everybody can get along? I'd like my fish to swim around and enjoy themselves instead of living in the corners. Perhaps I am overstocked? It seems there is plenty of room to swim around. I had this problem when I only had the SMB and the bluegill/pseed too though.