Marcus,
A friend had some hair algae on some base type rock, that refused to go away despite numerous cleaning.
After running PhosBan on my suggestion for some time now, its completely gone. He swears by the stuff. I guess he had phosphate problems.
However,
, he also added some calerpa to a section in his 100g sump, under a pair of 40w 65K shop lights. Not sure how much it helped but one must assume some. He ran my large turf scrubber when I was between tanks and still had the hair algae, although it helped his bubble algae problem.