Have a strange one..........I have always kept my nitrates at about 5 in a SPS dominant system. Recently I did some major equipment upgrades which caused me to remove my skimmer, UV, carbon, and GFO for several days. I expected my nutrients to be through the roof (no changes in feeding). I tested nitrates to find out that they were totally nonexistent. How could removing every form of nutrient removal I have cause my nitrates to bottom out?