Red Purple Slime Algae

[Reefer Rob]

How old is the system? If it's less than 6 months Cyano is just one of the phases it will go through. Eventually it will go away on it's own, but if you have to get rid of it now a 3 day black out will knock it back. Cutting your photo period back to 1/2 and then slowly bringing it back up after the cyano has disappeared will work too. Cyano is always present in aquariums, but will bloom when it can take advantage of a change.