I really don't know what's going on here

[Collinslice]

Those brown stringy things aren't algae. They belong to some kind of worm. Anyone have any idea what it might be? I can scoop it out and take more pics, but don't want to if it's gonna sting or bite haha

 

[Lionfish Lair]

Probably a spaghetti/hair worm. I would leave him alone.