I've got a 3" Jag that is over a year and a half old in a 75 gallon tank. Yes, you read that right. He eats well, the tank is well filtered, water is changed regularly and is maintained at 79 degrees. I'd like to put something else in with him, but he just attacks everything. I've only tried one at a time. How would I go about adding more cichlids to this tank? Adding 2 or 3 at a time? How many and what type of cichlids or other fish could I add with him?