Okay, I want to know the best route to go. I bought a 15'' common oscar to add in my 500 gallon with my other 2 common oscars. I knew I might have a problem buy adding the new oscar already having two might cause problems. 2 gang up on the new on. Yeah thats what kinda happend. The 10'' oscar beat up the 15 '' oscar bad. He is missing fins and lots of scales. The big oscar is a big wuss. So I moved the mean oscar to the 45 gallon. I am hoping that the big oscar can heal up in the 500. And buy hopes when he heals up and I add the mean oscar back the terrorties will be changed so the 10'' oscar will no longer own the tank. Is this the best way to do this? or should I add the 15'' oscar to the 45 and treat him? I am not sure what is the best way. Now the 15'' oscar in the 500 can heal with out being picked on.