I have a 4" Mbu that isn't showing any agression toward other fish. I have him in a 75G grow out tank with a couple american flagfish, a pleco, a fire eel, and a school of guppies. I wanted to get a good sized tankmate for the Mbu but I'm not sure which way to go. I was thinking one of the more mild cichlids but even there I'm in unfamilliar ground. Any suggestions? A tankmate that would eat the guppies would be a plus.