post a pic if you can so we can be sure.
If it is cyano and you are getting desperate, you can get a product called chemiclean and that is reef safe. Your corals will be pissed at your for about 3 days, but they will make it. Be careful though and not use it too much, cyano will eventually develop a resistance to chemiclean and it will no longer be effective. The first time you try it, your tank will be clean in about 2 days. Vacuum up as much cyano as you can before adding it to the tank.
I also would add phosguard to your sump (if you have one) to reduce the phosphate levels in your tank.
-Dr Marco :sfish: