Hey Brian its Brian.
I think the worm creature is exactly that a worm. Probably a tube worm. The tube worms are nocturnal, so you should only see them in low light or at night. They eat detritus and other waste products. It would be helpful to get a picture so that we can see if it is that type of worm or another. I believe some are good and some are bad so it would be helpful to see to be able to ID it.