what's in "my tank" right now? just fish? if so, i'd do some massive waterchanges, turn the light out for a week straight, and rip out all the hair algae i could before i covered the tank with a blanket(for the entire week, removing it just to feed, maybe more if needed).
if you have corals already, i'd implement a refugium ASAP, manual removal, and do massive waterchanges exporting as much nutrients as possible. i'd feed the fish about once a week for a while as well. it won't kill them. it might kill the hair algae though.