The problem is that organic phosphates are not detected by most test kits designed for the aquarium hobby . If you are at a level 0.03 of PO4 then you have problems you'll never achieve zero But you want to see as little color change when testing as possible. I'd worry more about the metals from the tap water myself.. I'd get a metal binding polymer and some aluminum or iron oxide for the PO4 as soon as you can. The sand and rocks have already absorbed some of the problem and will take a little while to be sure the tank is metal free. _________ Some of the world's greatest feats were accomplished by people not smart enough to know they were impossible (Doug Larson) |