Bubble algae, valonia, is a natural thing that often follows hair algae, sometimes appears with cyano coating it, which is what we have here. What is your nitrate level?
No need to toss the rock, pop or not pop the bubbles. They come and they go. You can pull the rock and scrub it with a toothbrush, but the main problem is with the tank, not the rock.
Do you have nitrate above 2?
Do you have a skimmer?
How much are you feeding?
How much skimmate are you getting out of the tank?