Hi! Welcome to Canreef!!!
Hair algae, what fun! NOT! I would just pick out as much as you can by hand, being careful not to get any floaties (they just land and start growing wherever). Then add some snails to help combat it. You might want to look at the reason you have hair algae though. What are your tank parameters? Do you run a skimmer? What kind of food do you feed? Something is fuelling the algae and you will have trouble getting rid of it permanently if you are somehow feeding its growth.