He has them all together, my two get along fine. They are like any pike, once they are stable you don't have problems, kept in groups they spread the aggression out. He sorts them by size so they don't eat each other and that's about it. I'm just trying to gage interest here to see if it's worth the outlay in cash. I don't need to spend all my money to get ten high dollar pikes if they are not going to sell, when I could get hundreds of Gymnogeophagus with the same money. Ken