Can anyone ID this

[Dsmall]

Looking for an ID and general info on them. Rather I should be worried and begin treating them or what to do.

These were found all over my sump walls. I removed all equipment and cleaned the sump and put everything back I know they will likely show up again as they've got to be in the water.

 

[EeyoreIsMySpiritAnimal]

Pineapple sponges. Sign of a healthy tank

 

[ISpeakForTheSeas]

Pineapple sponges. Sign of a healthy tank

+1 - harmless filter feeders. They're thought to be limited by silica in the tank, and they usually go away on their own after a while.

 

[ying yang]

+3 ^_^

 

[EricR]

I won't contradict anyone saying that they're basically harmless except to say:
-- found one inside a patch of zoas and it seemed to be irritating them so I picked it out.
-- month or two later, noticed another patch of zoas seeming (again) "irritated" by 4-5 clumped together so had to pick those out too.

 

[Dsmall]

Thank you all I appreciate it. However I did remove all of them I could find.