I'm new to this hobby and have been fighting algae of all colors. The things I've learned thus far are...
1: Increase the water flow in the tank.
2: Don't use old Bulbs in your Light Fixtures.
3: Nitrates are probably high.
Also check the phosphate levels.
If you increase the water flow in the tank it will help hold all the food and any other particles in the water long enough for the filter to suck it up. Without good flow everything will just settle on the rocks or sand and eventually start contributing to higher Nitrate levels.
I have a 90g Tank and I've increased my water flow to about 2000gph and its helped slow the algae down a lot. Plus I shortened my photo-period for the meanwhile. I only have my lights on for about 8 hours out of the day. And make sure your light bulbs are new.
Good luck. I know what a pain algae can be