what kind of cichlid from the amphilophus genus could fit comfortably in a 75 by itself or with a mate? and my brother would like to know if a female trimac could fit in 55 gallon. any opinions are appreciated.
55g is too small for a trimac. I think 75g should be sufficient for any single Amphilophus. At least I can't think of one that would get too big for a 75g off the top of my head.