Have a 55 gal. Hex tank, oak tand, oak canopy. Made a PVC, grate, screen plenum and added live aggregate (sp) and grunge on top of that. Live rock, some shrimp, 1 yellow sunfin, 1 Gobey, 2 clowns. Misc. snails. Rite now I am running a power head on a tube with air bubbles. Been running 3 weeks...