Let me talk from personal experience...its a little stressful cuz they want to eat your other fish. I have a lima catfish and the RTC just starting to bully him a little. But when I first introduced the RTC to the tank, he went up to the lima's tail and tried to put it in his mouth and he did it again (2weeks later). Then I also have a royal pleco and he pushes him around and goes at his body with his mouth, he's trying to eat him. So yeah, they are cool fish, especially when they get older cuz they change colors and whatnot but they are garbage disposals literally and will eat your fish when they get big enough

. I fed him 3x in one day frozen beefheart and he's still hungry. Thats why im going to give him 2 days to change his attitude and if he doesnt, i'll return him. I love my RTC, he has changed his color and his fins are more spread out, absolutely beautiful, he's my dog in a fish tank, but when u start messing around with my other fish, he's outta the tank. I wont have the other fish be stressed or eaten.