I had a bad hair algae bloom last year from over feeding I think. The fastest way to get rid of it is manually and I think it's worth the effort. Take a 30 gallon rubbermaid tub & suck out 10 or 20 gallons for a water change. Pull each rock out by hand & scrub gently with a toothbrush(take xtra care if anything is growing on the rock obviously), place clean rock into your sump or another tub with water change water in it. Once all the rocks are out & clean, clean your glass & sand if applicable. Your tank will look brand new, have a fresh water change & you can concentrate on preventing whatever caused it in the first place. It took me about 3 hours to do this to 150lbs of live rock in a 125 gallon, well worth it. remember, theres no room for laziness in this hobby
Good Luck.