I can't seem to find where you've posted your tank specs on the board here. Can you tell us about your system? Lights, how much LR, how much sand, if any, whether you have a sump or refugium, any regular maintenance that you do, water test results, ect?
Hair algae can be frustrating, and we can usually come up with a solution for your tank between all the regular members on this board here.
I'll post a hair algae link that some people have found useful:
http://reefs.org/phpBB2/viewtopic.php?t=6997
Mitch