Help with IDID

[Sully]

I have these growing in my HOB refugium. Haven't seen them just in the DT at all. White things on glass. Maybe a millimeter or two.
Side view and top down view.

 

[reef lover]

Maybe pineapple sponges or small tube worms....???

 

[Sully]

It's got a hard outer shell so definitely not a sponge. Thought it was snail babies at first buy it's developing what looks more like a tube. It's kind of a spiral on the glass.

 

[human]

Spirorbid Worms, harmless filter feeders.

 

[Sully]

That's it. Thanks.