Branching hydroids?

[carbondave]

Is this the start of branching hydroids? Right now it appears to be isolated to one piece of LR from TBS. I should note I just turned the lights on in this tank about a week ago, so it could also be the start of some algae. Should I take the rock out and kill it?

 

[ISpeakForTheSeas]

Yeah, those look like branching hydroids to me. You'd need clearer pics for a solid ID on them, but from what I can see it looks quite similar to Monotheca margaretta.

Edit: And, yeah, if you can remove the rock and clean it off, I probably would.