:-/ tubeworm/featherduster

i recently bought a feather duster (not sure if its a tube worm or feather duster actually)... its a long brown tube with a wormlike creature in it.
It looked fine in the pet shop but it hasnt opened since i put it in my tank (7 hrs). Whats going on with it? Where am i supposed to place it? The bottom segment of the tube is encrusted in sand...should i bury that part?
any help would be appreciated
 
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