Cyano suggestions

[gridley]

I'm looking for advice on dealing with cyano in our tank. We have a 90g tank that is still quite new - first added SW in August. We have seven fish so far, 5 turbo snails, 2 cleaner shrimp, a few hermit crabs and some sand snails. For filtration we have filter socks (change weekly) skimmer (clean weekly) GFO and carbon.

I had read about turning the lights off and reducing as much natural light as possible for a three day period. We went ahead and did that - I turned off the lights and wrapped the tank with a blanket - at the end of the three days the tank looked great - very clean.

Unfortunantly, one week later I noticed a suspicious growth and it is now clear that the cyano is back.

Suggestions please . . . and thanks