Percfan, There are many, many threads here about the problems and fixes of Cyano. We have all had the issue at one time or another to soem extent.
The number one cause of Cyano is excess nutrients! Work on cleaning up the water by increasing circulation by the addition of strategically placed powerheads and work on increasing the efficiency of your skimmer or purchase a more appropriatly sized skimmer. Increasing circulation to and from your sump (if you have one) will also help. More waterchanges and reduced feedings will also help.
Circulate and clean!
Voila! no cyano.
HTH