Is it just me or do others have better success with an ULNS rather that a low nutrient system? I've tried to have trace readings of 0.5ppm No3 and 0.02ppm Po4 and have had nothing but disaster on my SPS. Within a week of going back to ULNS my frags are coloring up and have seemed to stop STN from the base up. I do feed the tank with Reef Energy, Reef Roids, PE Mysis Flakes and I do not strain frozen food.