hey guys my question is ive been using tap since day one on my tank and i can seriously say ive never had a problem. its a fowlr,but within the past month or so i decided to put in a few mushrooms,polyps,suncorals,and some other corals ive bought from my fish guy.anyway since adding those i stopped using tap instead ive been buying ro water from the store or using fresh ocean saltwater for my top offs and waterchanges. more ro than ocean water.and ive been noticing more brown stains on the glass and sand that i clean almost everyday. anyone know why