Re: 2 new black sharks
If the Black Sharks are the type of black shark I am familiar with, they will squabble and they do get big fairly fast. I had one that lived ten years and was a foot long and sometimes they get even bigger. The Red Tail Black and the Rainbow are probably going to squabble. Red Tails like to play chase games with other fish. They have no teeth and cause little damage other than stressing the fish they pick on. Sometimes a Red Tail can be a docile curious fish with personality and on occasion do a short chase game. I got lucky with the one I kept, but gave a smaller one away because it was a hellion. Two Red Tails in the same tank can be trouble.