What the heck is this...?

[Ab129]

So I was away for two weeks last month and had someone come in and feed my fish. When I got home I noticed these clusters of bubbles popping up on my rocks. Figured they were a product of too much food being given while I was away. Today I realized that these clusters can be easily removed and they remain intact. The bubbles are the consistency of plastic almost.
Anyway, I'd like to know what they are and , more importantly, should I just pluck them out by hand or leave them be??

 

[colodano]

Bubble algae, pick them out, don't pop them in the tank.

 

[billdogg]

If the rocks are easily removed form your tank, even better. Take them out, carefully scrape off the bubbles, then put a small amount of hydrogen peroxide on the spot. Allow it to soak in for a couple minutes and then return the rock to the tank.

Bubble algae, if left unchecked, can quickly overrun a tank and then become a huge issue to deal with.