OKay got cyano now what?

[Ruth]

I think you would be just fine to cut back on your feeding as well. You can always pick it back up again if you notice your fish seem to be getting skinny.
You will probably have to upgrade tank size if you plan on keeping the naso - they do get very big. I have mine in a 190g with 2 other fish and it is almost too small - my tang is probably 12-14" long and all he will eat is nori and calerpa.