Help to Identify this

[jisherwood]

I have several of these growing in-between some of my rocks. This one I have attached is under a hammer coral that has been in the tanks for over 2 years. I guess my question do I need to be concerned or is it harmless and can ot be removed?

 

[JGT]

Looks like macroalgae or sponge. Sponge if white, macro algae if green.

 

[KrisReef]

Sponge. Remove if it overgrown the coral

 

[DoubleRReefing]

Sponge. Pretty harmless and cool filter feeder. I like keeping them around to diverse microfauna.

 

[jisherwood]

Well tha twas a really quick response. I agree itis white in color and if it is a sponge I can remove if it becomes an issue Thanks everyone for the responses