my phosphate levels always been high I can never can get it below .08 with a red sea tests. I am using dual chamber GFO reactor and using GRO PRO a lot of water changes and I can not get my phosphate down. yes I do have a lot of fish and big fish and of course I have to feed them a lot to keep all the tangs happy but I always wondered why my phosphate levels are high. today I did check my phosphate level from the RO/DI system and I have .08 coming out of it. no wonder why I cant win that battle. Commerce City water is the worst water out there. now I am trying new stuff and hope its going to work.