My soft corals have started to whiten up a bit. One went through a period of hyposalinity but some mushrooms I added yesterday whitened up. I placed them under an overhang but they are still white albeit a bit more open. I doubt that this is a light related issue as bulbs were replaced months ago and some of these softies and LPS have been exposed to them for months. My nitrates are 0 as tested by a salifert test kit twice. Any ideas as to how to restore color?