Don't :headwallblue: or :headwalls:. It's just part of a new tank maturing.
Go :beer: and :celeb3: instead.
You should look at your nitrate and phosphate numbers to make sure nothing is out of whack. But like Crazed said, if you keep up on your water changes and don't overfeed and it will go away. If you can siphon some out when you do your water changes it will help. Do you have a refugium? Macro algae like chaeto in the refugium will help too. Try to get flow on it will help too. If it starts getting really bad, like all over the rocks and everything, then you might need to look at nitrate and phosphate levels.