Help with ID

[ChamorroSD]

Just saw this on my live rock.
Is it good or harmful to tank?

Thanks in advance.

 

[saltyfilmfolks]

I think those are Xenia.
Free coral.

 

[Fish Werx]

Depends on who you ask! Lol! Looks like xenia to me. Freebie!

 

[Tautog]

Xenia, a keeper

 

[ChamorroSD]

Thanks y'all [emoji1417]

 

[TroutbumNV]

I agree, xenia.
It grows like a weed, so if its possible I would isolate the rock.