ID this bubble stuff Por Favor! : )

[kookerson]

Its been growing slowly, not causing any harm (yet)......one dismantled when I was doing something in the tank, so I took it out.......it seems that they are hard and hollow.......

[Briankook]

Looks like bubble algae .

[kawicivic]

valonia aka bubble algae

As long as you dont pop them all you should be ok.... as they get larger you should take them off (they are easier to get off the bigger they get)... they can become a nuisance. If popped they release spores throughout your tank and can choke out other stuff on the rock. Some emerald crabs will eat them and some tangs will eat it. I had some rock that was pretty bad but I just pulled as much off as i could and so far not too much has come back.