Your flow thorough the fuge should be in the range of 10x tank volume per hour. Meaning your fuge should recycle 550 gph
if you have a 55 gal
tank. This is the exact specs of my tank and I am having great results. Also don't forget to calculate the head height into your flow calculations, most pumps give you specific rates that their pumps pump at certain heights. I use the Rio pumps my self, cheap and I have had no problem with their dependability. The one I'm using in my sump was my main powerhead for the last year so I'm on the second year with no problems. And a simple Home Depot home made lighting fixture is the way to go, don't need fancy lighting to grow a little macro. My gallery shows my sump set up, though it's been updated with live rock and skimmer. Good luck.