Growing on coral

[Bpeckj]

What is this on side- underside of my elegant coral?

 

[carey]

Looks like a sponge to me, I have a huge one growing on the underside of one of my SPS coral. harmless if it is indeed a sponge. if you take it out of water though it should deflate and possibly die. :-(

 

[Bpeckj]

Would that make it not want to open completely?

 

[carey]

No it shouldnt...it cvould be something else then...lets' see what the experts say. i was just guessing cause its common for them to be in a tank under a coral.