I think I know which algae you're talking about. LOL ... I like the way you named it, "hairy" hehe ;D In fact I have this algae growing on my driftwood from time to time. I remove it by hand or with small tweezers. They're easy to remove. Don't scratch them off, just pull them. I think they're an attractive type of algae. I think I might let them grow on my driftwood - they're kind of cool.