Over the last 2 weeks I have noticed that I was getting a lot more cyano in my main display. and this morning I saw a tiny piece of calupra growing on a rock. I have not had calupra in the system for years now! I don't care about the calupra but do you know any tricks or tweeks I can do to my scrubber to help beat back the cyano? I tried the lights off for 3 days and ALL the cyano is still there I feed flake & homemade frozen foods 3 times a day FWIW. I add 1 tsp. of Iron every time I clean scrubber FWIW