ID White Hairs

[superknuckles]

I’m looking to ID a hitch hiker that’s been invading my reef tank. The best way I can describe it is [short white hairs that grow individually on live rock].
I first found them on a Acan frag I got, which I did dip prior to placing in tank (In photograph). Now they have spread on all of my rocks and the invasive manner of them is starting to freak me out. I haven’t noticed any significant stinging or irritation to anything in my reef.
If they are harmless then I’ll leave it be but I’d like to know of any hazards just in case. I haven’t found anything online that looks identical to these white hairs.

 

[KrisReef]

Your description makes me think that you might have Hydroids in your tank?

Sometimes they just fade away and other times they grow into a plague. Not sure what you have, ?