What is this ?

[actik]

It's about 3-4 inches long showed up recently kinda gives me the creeps not knowing what it could be haha. Like a tube made in my substrate

 

[DSC reef]

Possibly a spionid worm.

 

[AdamB]

More than likely a spaghetti worm.i had those in my old tank . Harmless ...

 

[actik]

Thanks, that actually gives me the chills haha, not even sure how it got in there i havnt added anything in a good while

 

[vetteguy53081]

Looks like a tube left behind by feather duster or spaghetti worm

 

[DSC reef]

Thanks, that actually gives me the chills haha, not even sure how it got in there i havnt added anything in a good while

Spionid worms can use the substrate like that. All the worms mentioned here are actually good for biodiversity and clean up crew so I wouldn't worry.