is your tank reef ready or are you going to use an overflow box? most reef ready 55 gal
tanks have a one inch bulkhead for the drain line, which wont be large for a no powerhead system. this is what i have, and am just like you, i hate the look of powerheads in my tank. i have a quiet one pump rated at 800 gph
, but my one inch drain wont even handle 600 gph
, so i have turned down using a ball valve, and use the PHs.
if you dont have a reef ready and are going to buy an overflow box, make sure you get one rated at least 800 gph
, this way you wont need any PHs, and i would actually go with two returns.
in a 55 is a little much. youll be blowing your coral all around the tank. i think 600-800 gph
would be suficient. i have about 600-700 right now and everyone seems very happy, especially my xenia whom can actually pulse now and not get blown away.