So after having a cyano outbreak like never before I used chemiclean . I had outbreaks before but usually it would go away after a few weeks and things would be fine. This time it was getting bad and I figured I would try it. After a day my five was clear but the DT still had a fair amount. I was worried about using this stuff so I only does enough to treat 300 gallons and my system is around 350. So after 2 days I still had some in DT but as the directions state it was time to remove it. Even on the third day some was still there . Today it is all gone. All corals ,fish, clam and Ben are all fine if not better.