hair algae is THEE worst type of algae u can get because it grows fast and spreads fast and looks ugly. i have had this problem for a good year now and in this year i have bought lawnmower blennies, which i herd will eat the algae over time but i have not had any luck so far, i also bought a sea hare. a sea hare will get rid of ur algae problem for sure but i bought one and it died after like 5 days. i would go with the sea hare. so any way my sea hare died and i am sick and tired of battling this losing war with hair algae. i am using ALGAEFIX MARINE as my last resort. its not a good idea to use chemicals in ur tank. its good to keep it all natural but im so tired of this algae i cant take it anymore. it looks soooo ugly! so this chemical kills the algae.then u can suck it up with a tube. its reef safe (thanks God). good luck.