I had a Leo Danio in my guppy/tetra/platy tank. He got very mean and was terrorizing everybody. I tried adding a couple of Zebra Danios he wouldn't swim much with them. I tried him all by himself in a Q-tank... but he looked miserable. Tonight I put him in with the "Big Boys". He's in with a 1 Irid Shark, 3 Grouamis, 2 Silver Dollars, and 2 Plecos. He went from being the largest fish in the tank to that smallest? So far he seems OK. But is this cruel and unusual punishment to move him this way?