I've been running Nitra guard now for a couple weeks. The Nitra Guard starts off white and looks like Styrofoam chunks, is now turning dark red. I've heard it should change black before it starts working so not sure if red is a normal phase. My Nitrates are still high, although maybe slightly better than before. I'm guessing between 80-160 on my API kit. Still doing 20g water changes once a week. I know more g and more often would be ideal but without my own RODI its not convenient. I have an RODI from BRS sitting in port huron, just got to find time to go get it. Fish, Corals, snails, crabs, all seem very healthy. PH, Nitrites, ammonia, salt are all where they should be.