Hey Mike, I caught what you said about having to clean your live rock due to some algae problems. I have a 46 gal. bowfront, two powerheads, overflow/wet/dry with Aqua C Urchin skimmer, along with a few fish, some cleaner blue leg crags, snails. I also have some softies, mushrooms, yellow toadstool, rose tip anemone, zoas, etc., all doing great. This is my 2nd sw tank, I sold my old one a fews years ago and started this one, BUT bought my live rock from Florida instead of buying actual Fiji live rock from other sources. This live rock grows "stuff" that is invasive and keeping my corals from expanding and growing as they should. Some of the stuff that is growing on one particular rock is like moss, green moss, which is really hard to pull off and it is starting to spread and the other is light, grey green fuzzy, also hard to pull off. It's not cyano. How did you clean your live rock without killing the corals on it and what did you clean it with? I honestly don't know that I can clean this stuff off the rock. I wonder if there is anything that would eat this stuff. Thanks for any suggestions. ~ Linda