What Are These?

[Cool Fish]

I’m trying to grow the bacterium infrastructure of my aquarium and while finally having some success, I happened to notice what I thought might be copepods in my refugium, but I believe are too large. Look at the video. I'm talking about the long, almost worm-like critters. But they have antennae. So, what are they? Friend or foe?

 

[WheatToast]

It's a little hard to tell under the pinkish lighting, but here is what I am seeing:
Munnid isopods, harmless grazers and one of the rarer "pods:"

Copepods, much smaller than the munnid isopods, some appear to have eggs in tow:

Spirorbid worms, harmless, filter-feeding tube worms that are common in new tanks:

 

[Cool Fish]

It's a little hard to tell under the pinkish lighting, but here is what I am seeing:
Munnid isopods, harmless grazers and one of the rarer "pods:"

Copepods, much smaller than the munnid isopods, some appear to have eggs in tow:

Spirorbid worms, harmless, filter-feeding tube worms that are common in new tanks:

Oh, that's good news! Yes, they are hard to see. Thanks!