green bubble

[feixjai]

i got a piece of rock that came with many many brown mushrooms and i noticed that there was a green bubble on it. i didnt know what it was and if i poped it, it could let something toxic in my tank so i left it. and now it got a lot bigger it is now about a little less than half an inch. is this bad or good? it there a way to get it out. i just had a cyano problem that i had got rid of already.

 

[kdfrosty]

Sounds like bubble algae. Definitely don't pop as a precautionary measure....it could cause the bubble algae to spread. For a definitive answer post a pic.
In the event that it is bubble algae, it's an Emerald Crab's favorite delight. They're a great reef creature anyways.
Post a pic...we'll see.
HTH

 

[airforceb2]

If it looks like a shiny green marble...it is bubble algae. DO NOT POP IT. Popping it will release millions of spores in the water and you will have a tank full of green marbles. You can either take the rock out and scrub it off with a stiff bristled brush or get an emerald crab. You said it was covered with shrooms so I'm going to bet you don't want to scrub it.