Sponge or something else?

[Andrew_3896]

Hi,
A while back one of my snails developed a white ball on its shell. After a bit of research it didn’t seem to be a problem. Now it is much bigger and had thing pointing out of it. I now also have something growing on my coral and rock. What is it and is it bad.
Thanks.

 

[DSC reef]

All sponges, harmless filter feeders.

 

[mta_morrow]

All sponges, harmless filter feeders.

Yup^^^^^

 

[jeffchapok]

The last 2 are definitely pineapple sponges.

 

[Andrew_3896]

Ok, thanks.

 

[Txplicit]

Harmless, but they do multiply really fast. So keep an eye on that