I usaully use RO or distilled water that I buy from the store but when I upgraded to a 120 gal. from a 72 gal. that would of been a lot of water to buy. So I used filtered water from the tap thinking it would remove most of the bad stuff. Well it didn't remove the phosphates, it removed everything else. So now I'm stuck with high phosphates. I have every time of filtration there is: live rock, DSB, magnum 350 which has a bag of phos-ban in it, emporior 400, and in the sump I have live rock, calerapia algea, and contaner filled with reef carbon. I never ran into a problem like this before so I'll go get some different removers today and try them.