I had been fighting a bad case of cyano for about a month. I tried a 4 day blackout, massive water changes and even peroxide with no results. I bought some of the red slime remover as a totally frustrated resort. I was very concerned about using another chemical in my tank, plus side affects can be very bad. This stuff is amazing! After following directions to a T, the cyano was completely gone in 48 hours, not even a trace left in the sand bed. I did not see any stress to corals, fish or cuc. If you have cyano and try this product I hope you have the same amazingly fantastic results I had. Cyano free now for almost 2 weeks! :bounce: Hope I'm not breaking any forum rules posting this, just wanted to share my experience. If I have broken any rules, please just delete my post.