BTW: Paul - a VERY warm welcome to MASA!
Paul:
The basics in removing cyano, are the following:
- run your tank/water with as low nutrients as possible
- ensure that you have MORE than a lot of water flow inside the tank
- ensure that your substrate/live rock/base rock does not have locked in or hidded detritus (use a turkey baster, as Kanga suggested, or a loose power head - blow in/around the live rock - the detritus looks like fine "dust" that get's blown into the water column).
What size skimmer do you have? It might also be that the skimmer is under-rated for your size tank.....
You might have/had a lot of die-off on/in the live rock.... this could possibly have released/leached a lot of nitrates/phosphates into the water, feeding the cyano bacteria.
BTW: just take into account that cyano bacteria is not really a "BAD" thing. It just looks icky......
Good luck in eradicating your "issue"....