Snails and crabs will eat it, but you can't let it get long
'rip it off with your finges and they should eat the rest. Make sure that you stop your feeding for a few days too, this will force them to look for other sources of food, If your feeding them at the same time as trying to rid the tank of hair algae, you will lose. Also, reduce the lighting for the time it takes to get rid of it. If it is on live rock that has no corals on it, turn it upside down, this will kill the algae as it needs light to survive. Boost up your water flow, this helps. Other critters that help a lot if the algae is not too long, lawnmower blennys, they are great and fun to watch when they attack the hair algae, blue legged hermit crabs work to, but REMEMBER not to feed your tank while trying to rid it of hair algae. The other solution that works too is to add a "good" macroalgae into the tank, check my other recent posts about herringbone algae. Good algaes will compete for the nutrients in the tank. That combined with your cleanup crew and less feeding should clear it up within a week or 2. good luck.
