I have had my miniatus grouper for 6 months now and he is the king of the tank. Before I got him I had a picasso trigger in there for 6 months and then waited 6 months to add the grouper. The trigger took a snap at the grouper and the grouper snapped back. Ever since the miniatus grouper is king of the tank. My grouper comes out all the time to mess with trigger so I bought a tank divider system to separate them. I think it is a hit or miss on if the grouper will be aggressive or not. (Ha.. I was afraid the picasso would pick on the grouper) Other than that the grouper is very easy to keep and eats great. Make sure you get one that is very bright and looks healty in the fish store. Good luck and I hope this helps.