you can have other fish with the redtail they just have to be big enough not to fit in it's mouth. I would say 80% the size of the adult RTC or bigger. I lost a 14" oscar to a 22" RTC a few years back, he also ate my columbian gar, several small pacus, and all the minnows, chubs, and panfish I could trap out of the creek behind my house. I put a 5lb. large mouth bass in with him when he was around 26". that bass just happened to be the right shape and size to barely fit in his mouth. Took him 2 weeks and lots of water changes for him to digest it. Currently my monster 27" RTCxTSN cross eats about 1/2 lb. of market fresh jumbo shrimp or prawn every other day. Ocassionally I will catch wild fish to feed to him, usually nothing over 12" though. I also feed him large floating hikari cichlid pellets every night. He currently lives with three smaller fish. The only one that I am worried about is much smaller. To tell the truth I don't know why he hasn't eaten it yet. It is another hybrid that is only 16"(TSNxblochii)
