Hair algae on your glass? It usually grows on the rocks.
The root of the problem is excessive nutrients. I'd test for nitrate and phosphate. If that is zero, then it's because the hair algae has absorbed all the nutrients. The solution is to push things to zero.
When I first started, I had big problems but I kept cutting back on feedings, added a phosphate reacter, protein skimmer, mechanical filter, etc. until things finally stablized.
I've also used SeaChem Stability which has the bacteria you need for the tank. I suspect I just needed to seed the tank properly, so you could also "borrow" a few gallons of water from a friend.
