How much media are you running and for what size display and is it plumbed correctly so the flow is bottom up to lift the media? Too much media can cause a number of problems including compacting and bleaching of SPS corals and irritation of soft corals. 1 tablespoon or 10 grams per 10 gallons is full dose and I prefer to run 1/2 of that at all times once I get phosphates under control as a precautionary measure. I never run full dose. Also BRS has this harebrained idea to run twice as much media and ANY other supplier, manufacturer or vendor and while I use their media I will not use their lame instructions.