my 55 has 8 glosfish, 12 guppies, 4 neon rainbows, 1 RTBS, 1 clown pleco and some common snails. I will be moving the lone angel (50 cent size) in 2 or 3 weeks; as soon as the new angels in the 37 have thoroughly acclimated. the 37 will house the 3 angels ONLY (along with a couple of apple snails). If I need to I will put in an oto or 3 for cleaning crew.