Hi Ryan I graduated Oakland High School in the 'boro, 1981. A hair algae is not a specific term, and is used to describe any finely filamented algae. Derbesia and Bryopsis are common algae in reef tanks and the most likely to be called "hair" algae.
Algaefix is dimethyliminoethylene dichloride and ethoxylate. Its meant for use in freshwater tanks. I'm no chemist but IMO it is potentially harmful to reef invertebrates and perhaps some of your fish. Control of algae in reef tanks is primarily through limiting the nutrient supply, providing directed nutrient uptake (harvested algae in refugia), and grazers. Some reefers use methods that enhance bacterial uptake of nutrients such as vodka dosing and "zeo" products. Things that kill plants directly have the potential to kill some coral, as well, due to the dinoflagelate algae some coral host within their tissue.
If you want to try chemical control of algae research the product Boyd's Chemi-clean, which is intended for marine aquariums and I know has been used in some reef aquariums housing sensitive coral.
http://www.aquariumpros.com/p-BOY16714.html It appears to be a potent oxidizer so I would be cautious in using it and ask or search around on other boards (like the general board or the SPS board) about experience using it in tanks with coral.