I'm sick and tired of listening to my noisy air pump for my 38's undergravel filter. I've thought about powerheads before, but would that be feasible for a tank that size? It's 36"x12"x20"-ish. Can I just use one powerhead on one end of the tank, or should I put two smaller ones on each end? And is a total of 150-200gph okay for it? Thanks!