Blennies

If it would be any blenny, it would be the lawnmower blenny. Have you tried the huge turbo snails?

 

The lawnmower blennie does a good job but def the turbo snails will do it but you will have to cut or trim the hair algae

 

A foxface does a real good job of eating it

 

i have the best luck with emerald crabs, in fact, they always attack it when it comes in on frag plugs within 10 minutes of hitting the water

 

+1 on the emerald crabs---however, IMO you will want to get on this right away so the hair algae doesn't get out of control, I had hair algae way bad! I've finally got it under control but it took about 4 mos. of picking it off to do so.
Good Luck, John

 

def emerald crabs and large turbo snails.

 

Getting something to eat it will only solve the symptoms of the problem. You should really try to find out why the hair algae is growing in the first place(old bulbs, low flow, high nutrients, old food, etc...).

 

If it is an Astrea, then it isn't what most people call a "Turbo" snail. Astrea shells look  like a dunce cap. Turbo would be like this pic below. A big one will be about the size of a baseball. My single turbo ate all of my hair algae within two weeks and does the work of all my other snails combined! In their spare time, they love to knock over unfixed frags off of rockwork and take long walks on the beach.