This is not a sure fire cure but raising your calcium levels will help fight algae.

Adding the new light will also help. I have found that as bulbs get older and the spectrum reduces the algae is still getting what it needs to grow but your corals don't. The corals won't die but they won't flourish and the algae overgrows them.

Pulling out what you can by hand will give you a leg up as the tank tries to fight the algae.