Right now my 45 is the tank of reject fish - it's got a couple of bolivian rams, a couple of longfin rosy barbs and a school of gold barbs. My tentative plan is to get rid of the remaining tiger barbs and move them all over to the 55, which would free up the 45 for........ I had been wanting crayfish again. I COULD go with crayfish and tiger barbs, something I've done before. Anyone have any ideas? The tank is a tall 45, 36x12 footprint. fluval 405 for filtration.