What is this

[saltysailor]

Saw it on my frag plug looks kind of opaque but large and had some sort of the thing at the top. I think are smaller less thick ones too.

 

[saltysailor]

He’s another on my snail?

 

[SHNICI]

Pineapple sponge, filter feeder reef safe.

Can you compare here Pineapple Sponge, just in case to confirm Please (can't see them from the 1st 2 photos)

 

[saltysailor]

Thank god, there are so many of them! How do I keep population in check.

 

[SHNICI]

Thank god, there are so many of them! How do I keep population in check.

you can't, they are harmless filter feeders, I had thousands of them. most of the time they will reduce by them self .