i was thinkin 2-4 but I read so much about them pairing and gettin super agressive when matingand wil kill off oher convicts and any other fish.but some say if the tank is big enough they wont bother and im not sure if a 55 gallon is enough room for up to 4 convicts and mybe 2 other chichlids around the same size. and that why I decided not to go with the green terror because thy can get pretty big. I wanna be able to get another fish type hat can hold its own. or 1 more of one kind and one more of another.