Been dealing with Cyano since February. I’ve had Chemiclean to use but have been exhausting all other natural methods before I use it. I must say, I’m really impressed with Tropic Marin Cyo Control. I completed the final dose today (which is why the water is a little cloudy temporarily) and it has reduced the Cyano by 75% so far. Paired with some maintenance changes, removing the Cyano before each of the 3 doses, it’s really impressive how things are clearing up. Even the back wall almost completely cleared up after the first dose. 💪🏻💪🏻