Clean up crew for red cyano?

im not sure about snail and crabs but a dragon gobie will keep it off the sand.

Start looking at other parameters that encourage cyano. Water flow, nitrates, low alkalinity, low pH--all can allow cyano to thrive. Very few animals will eat it. I used to have a reef and a FO plumbed together. The reef never has a scrap of cyano, but the FO would get covered. The difference wasn't the water quality, but rather the number of cleaners and such that moved around the tank--they didn't eat it, but their movements prevented it from establishing. So, if you don't have many cleaners, adding some will help--but you'll have to remove it manually for quite some time until their efforts will be able to keep it at bay, IME.