Small air bubbles on SPS

[Marineman]

I have place a sps on top of the tank with 150 w MH, some of my rocks has air bubbles, tank is 2 years old. Can someone tell me whether the tiny air bubbles on the sps harmful? Should I blast it off with a tube or its it because of too much light. The sps was initially located in the middle section of the tank. Now at the top, looks like it's turning slightly brown with tiny air bubbles on it, please advise. Thanks.

[pangz]

Think someone mentioned it before. The brown stuff is algae growing on the skeleton of SPS. Hence the air bubbles produced by the algae. The tissue on the tips of your SPS could have been blown off by your wavemaker. Maybe you should check your placement.