I have noticed that having a refugium on one of my tanks that it is possible to not only reduce nitrates and phosphates, but also help stabilize ph as well. I have also notice that ph starts dropping after the lights go out. So running the refugium lights on a reverse photo period has a profound effect on PH. I have read, and believe, that there is a drop in this effect at about 6 hours. So running two with overlapping photo periods would be the best solution. We’ll see...