Hi.. I'm Vicki and I'm new here. We have 2 tanks... a 55 gallon and a 10 gallon. We have 1 Oscar, 1 Needlenose Gar, 2 Tiger Barbs, 1 Catfish, 1 Shark, 2 Chinese Algae Eaters and 1 Placo in the 55 gallon. The 10 gallon was originally for the feeders but quickly housed a black ghost knife. My daughter did a bunch of research... decided the ghost knife would be ok with Oscar so picked one up... the knife fish nearly got eaten so we moved him.