I was looking in my sump and found these white worm looking things. Initially I thought it could be a spirobid worm but they're not in the typical spiral (if that matters?). Does anyone know what they are? Thanks for your help!
Yeah, it looks like it's probably some kind of feather duster worm (spirorbid worms being a more specific type of feather duster known for the coiled tubes they build).
Edit: so, it's probably a harmless filter feeder. Welcome to Reef2Reef!
I still think they are probably spirobids.
I do actually run spirobid farm in one of my tanks and most of them are spiral, but not all.
Either way I accepted my spirobids as a part of biodiversity, they are much more friendly than Aiptasia, although they do consume Ca and dKH stealing it from my corals.