Calling on the worm gods, what is this?

[Bd.reef]

So these f*ckersbbb have taken out 2 chalice and 3 torch colonies. I find them burried in the skeleton and are around and inch long. What is it and how do I kill them?

 

[Timfish]

Ceti Alpha VI sand eel.

On a more serious note, it looks like a brisstle worm of some kind but better pictures showing a close up of the head and body would help. I would also suggest considering there may be some other issue with the corals and these worms are just scavengers and doing their job of cleaning up. Corals can be seriously ill but not show any visual indicators until they die. I'd look closely at thier history for the last few months to see if there was some stress event or variable that's changed.

 

[Bucs20fan]

As im not sure what type of worm they are, Prazi pro has been known to kill several different kinds of worms and it is reef safe.