Id please

[salth20newbie]

Hi, I need a couple of IDs. One is a picture of string like "things" that are pulling my hermit crabs exoskeleton. The strings are pinkish in color with black dotted segments.

The next picture is of two calcium looking tubes that have something growing out of each end.

The third picture is of a small brownish branched looking organism that has a bush-like appearance.

 

[SushiGirl]

Probably a spaghetti worm.
Featherduster tubes.
Can't tell on the last one, maybe the start of algae?

 

[Sugar Magnolia]

First one is a cirratulid worm. Harmless.
Second, feather duster tubes.
Last, looks like hookweed. Hypnea cervicornis maybe.