Vitz totally agree, but cyano doesn't always survive in the man tank because of diffrent lighting increased water flow etc etc.I do agree with tackling the source though,but I also feel cyano in the sump/fuge helps speed up the burning off the excess nutrients,I see the cyano in the fuge as stealing po4 from the show tank,combine this with improved practises and your well on your way, all the best reefguide, cheers Daz