Here's what you do. When doing a water change get 2 five gallon buckets. Fill both with water your pulling from the tank. Place the rock in bucket 1 and scrub the **** out of it. Place recently cleaned rock in bucket number 2. Repeat until rock is clean. You may need to dump bucket 1 and refill with water from your tank.
Replace the rock when done. Cut your lighting to 8 hours aday.
This will get it under control. Then get yourself an algae blenny. He/she will keep your freshly scrubbed rocks in check. This is what I did to my 130 and I have nothing left, it's been about a month and the blenny is fine and I can watch him ripping off whatever might begin to grow.