I get the feeling this ain't GOOD algae

[andsoitgoes]

It was spreading like the DICKENS though, I roughed the shroom off of the rock, looked more closely and that's for sure what it was.

I'd like to keep the rock, so I've done a good clean, the second I see anything come back though, that's it. I may see if I can save the other critters in the rock (mini brittle stars, and such) but otherwise rock go bye bye, disappointing, it's a pretty rock.

The last thing I need is a nasty cyano outbreak in my tank *shudder* - Not make me happy.