Can some one help me ID this

[knazem]

I just added 2 peppermint shrimp and sand sifting snails i know this isn't the snails but i noticed it the day after can it be a coco worm or feather duster of any kind? (see picture) this is a fairly new tank no fish or coral yet
Water Parameters:
PH: 8.0
Ammonia: 0
Nitrite: 2.0 (shot up after adding shrimp and sand sifting snails was at .25)
Nitrate:80 (shot up after adding shrimp and sand sifting snails was at 20)

Contains:
2 reef hermit crabs
2 red crabs
2 mexican turbo snails
2 sand sifting snails
2 pepermint shrimp

[Original Fin]

Just keep an eye on it. If it's a snail it will move, if it's a duster, the crown will come out eventually.

[knazem]

It hasnt moved and i see my snails all over the tank but this just sits still....if it is a worm how long before i see anything?