I'm running one 55 gallon with a pretty hefty bioload, it's got 1 convict, 2 BP's, 1 Angel, 2 Dwarf gourami's, 2 Clown loaches, 1 Weather loach, 1 Ropefish, and 20 or so feeder whiteclouds. Now i know that is alot but most of them are just in there to grow and and will be moved to other tanks...