Fwiw, I find just the opposite in my tanks, the nitrates are high enough without any chem additions but the ortho-phosphate tends to run low unless I add it. My water starts out with very little of anything in it from the tap. A GH and KH around 2, pH=7.0, etc. So what I get comes from the foods and the ferts. I guess a lot of foods don't have much phosphorus in them anymore. Scott H. __________________________________ Do you Yahoo!? The New Yahoo! Search - Faster. Easier. Bingo. http://search.yahoo.com ------------------ To unsubscribe from this list, please send mail to majordomo@thekrib.com with "Unsubscribe aga-member" in the body of the message. Archives of this list can be found at http://lists.thekrib.com/aga-member/