Im a am preparring to ad a 10 gal. refugium to my 60 gal. tank. I would like to place the fuge above the tank. My question is should I use an overflow box to return water to the main tank? And should I place my powerhead in the main tank pushing water to the fuge? Or, should I use th PH in the fuge to pull water from the main tank? Also if you are planting macro in a fuge to use up nitrites and nitrates, why can't this be considered and algae scrubber???