Weird orange growth on hammer coral base?

[F.H]

looks like a sponge, harmless. Actually helps filter the water. Just make sure it doesn't go over the tissue of the hammer as that might irritate it (it shouldn't but keep an eye on it).

As long as the hammer is puffy and happy, nothing to worry about.

Does it look like the "orange encrusting bath sponge" in this link?

http://www.reeffarmers.com/farmsponge.htm