Two nights ago, I checked the nitrates and they were around 2ppm. I'm starting to see some changes in some corals, so I've decided to wean the system off the AZNO3 product. Specifically, the bubble coral looks smaller, the anemones looked shiny, and a couple of twigs of SPS RTN'd. Since I've reduced the NO3 significantly, I think the product did what I needed. Hopefully it will handle the weaning-off period. If it does, then I can recommend this product to others in the future without reservations.