If the cyano is only in your fuge, I truthfully wouldn't worry about it too much. Cyano is extremely efficient at nutrient export, and in your particular case, I believe it's doing more good than harm. Generally, if cyano is only growing in the fuge, it is due to low flow. Detritus will start to build up and fuel the cyano. I'd say the best way to get rid of it would be to syphon out as much as you can and then add a small powerhead to your refugium, mainly to keep things ont he bottom stirred up so detritus does not settle. It may take a few weeks to a couple months, but that will probably fix your problem.
