Should I be concerned with this worm?

[Chris's Fishes]

So, I've seen this guy quite a bit over the past month or so, and he's been growing pretty quickly. Bristle worms don't usually bother me, and I know that it's sorta common to freak out over them, but he's getting pretty big. Is this a valuable CUC member, or will he turn into a menace? So far, no damage has been done, to my knowledge. 

 

The picture isn't stellar, but it's what I could get with the lights off without scaring him away. Also, excuse the algae!

 

[MrObscura]

Usually they're beneficial. Unless it gets huge and noticeably causes issues I wouldn't worry about him. 

[Chris's Fishes]

4 minutes ago, MrObscura said:

Usually they're beneficial. Unless it gets huge and noticeably causes issues I wouldn't worry about him. 

Yeah, that's what I've been thinking. I just wanted to know if he was easily ID'd as a pest.

[OPtasia]

It's a bristleworm. Sometimes called a fire worm. They can bite/string you if you touch them bare handed.

 

If you have actual live rock in your tank, chances are you have a bunch of them. They're only hazardous to your reef if theyr'e larger sized and have nothing to eat. In ultra low nutrient tanks, they can go after corals and inverts if they're starving. Otherwise, they make pretty good detritus eaters.