hey sal.i just had an outbreak.what i did was change my filters in ro/di,added more chaeto in my fuge,changed out my media in my phosban reactor,heavy skimming and waited 5 days and let the cyano grow for 5 days before i syphoned it out.i alsocut my light cycle down 2 hours extra a day and am now feeding less.its due to phosphates in your tank.dont quick fix it it will come back.get to the root of the problem