weird 5 mm things on glass-not spirobid

[joegoersch]

I have these white kinda fluffy things all over glass and pump surfaces in refugium. They are small, maybe 5 mm, and stick to glass and have a shape to them, kinda like, well, goldfish crackers.

Any ideas ?

Thanks.

 

[Widdy]

Pineapple sponges.

 

[Turbovr3six]

Looks like that to me as well. They're harmless

 

[joegoersch]

Yup! That's what they are.
Thanks.