If you want to see carnage get a Parachromis Dovii (the Wolf Cichild). Smart ill-tempered and huge the male is 30" and pure evil. Nasty teeth areal one fish only tank. I had a close relative (the jaguar cichlid) and it had a nasty habit of biting the heads clean off the feeder and the Dovii is bigger. Adult would kill a school of pireaha in a week. The KING hands down.