API algaefix works pretty well against hair and thread algae. Problem really is these algaes thrive in the same conditions when plants thrive. A blackout will hurt it as well. If you dose algaefix be warned it might kill your inverts. You can dose it at the reccomended dosage 1 each day for 3 days then wait a week and do a WC. Bottle tells you to dose each 3 days or something. But you can just do it gradually over just 3 days. I did that and my shrimp (cherry and fire) were fine. Although lots of people have also reported mortality so, once again you have been warned.