I have always had the problem of low nitrates with high phosphates, and have tried many methods to get the nutrient levels in balance. I found that by using lanthanium chloride, I could never "balance" the 2 levels to hit a happy constant for both. What eventually worked for me was to couple kno3 dosing with carbon dosing such that the increased nitrates and carbon ended up bringing the phosphates lower naturally in natural ratios. After I brought both levels to an acceptable ratio (5ppm nitrate, 0.05 phosphate) I switched to dosing TM Bacto Balance to maintain the levels (since Bacto Balance is supposed to add phosphate and nitrate back in addition to carbon dosing to maintain acceptable levels). Unexpectedly, my nitrate dropped to a constant 0.2 and phosphate to a constant 0.01-0.02. Despite these very low levels, my corals have not paled out and still maintain the same level of colouration as when the system was at 5ppm nitrate and 0.05ppm phosphate. I believe that the Bacto Balance is helping the system process the nutrients better such that the corals are still getting enough, but measured levels are very low.
