Good or bad?

[Isda]

I found these little things growing on the glass and a few on the rocks. After going through numerous sites I finally found a pic to post here since my camera (or user ) is incapable of taking a clear focused picture. However, my search did not lead me to any info if this is good, bad or acceptable.

Some serpulids are tiny, down to barely noticeable with the naked eye. Here are some calcium tube dwelling ones on a relatively large Sea Squirt in N. Sulawesi. Smaller than pinhead size.

[ChrisPrusha]

I think they're fine.