Are these feather dusters?

[Jon0807]

I have a bunch of feather dusters with red feeders, but the tube itself is usually white. I've been finding these for a while now, but I'm not sure if they are the beginnings of a feather duster or if they are something else. I don't ever see any "feeders" coming out of them. I'm talking about the clear tubes coming out of the rocks.

https://farm5.staticflickr.com/4468/36704933344_4f16ae4081_z.jpg

[mcgyvr]

type of sponge..

[Jon0807]

type of sponge..

Is that good or bad? They must've come in on a frag and survived a coral dip cause the rock is the BRS reef saver stuff

[LeJeune981]

Do they have like a curly base on them?
I get those in my tank as well.. no idea what they are

[mcgyvr]

Is that good or bad? They must've come in on a frag and survived a coral dip cause the rock is the BRS reef saver stuff

Totally fine/harmless..

[mcgyvr]

Do they have like a curly base on them?
I get those in my tank as well.. no idea what they are

That sounds like vermetid snails..
They can irritate corals sometimes with their mucus net/string but in general don't cause any issues..