This is in my womens 55 gallon. The syno is about 3 years old, perhaps 5". She used to have a lace catfish that thing was semi aggressive and we knew for a fact it ate other fish. She can only manage to keep 1 glo lite in the tank the rest get eaten, so yesterday I bought 4 more, 2 blue, 1 purple and 1 red. So she had a total of five. Well now she has 2, the original glo lite and a blue one. Tank mates are 1 clown pleco 2"ish, 1 syno decorus 5" and 1 dalmation molly 1.5". I know fish eat other fish blah blah, but a 5" decorus eating a 1" glo lite? Iv never seen him bother anyone. $18 snack is pretty expensive....