Never thought about that until today... I DO run a phosphate reactor. But I also have been dosing extra sugar during the day to make sure a food source remains for the bacteria. My water is clearer than ever and my skimmate is nastier than ever. Corals look great, too, but there has seemed to have been a slow down in growth lately. I think it is related to flow, though, as the corals have increased their mass, and I am looking into increased flow options (Vortechs) in the near future...