White hairlike growth on live rock

[Not Clowning Around]

Hello all
New reefer tank is 5 months old but started with live rock and correct reef crystals for a reef. Tank is doing great. Fish are loving life and anmemoe are thriving. I have been noticing white hairlike growth on only one of my live rocks. Water parameters are all in line except phosphate a little high but will doing a water change today. They aren't slimy and I can't even brush them off with a toothbrush. Should I be concerned or remove the rock before it spreads? Any help appreciated.

 

[WheatToast]

Pictures?

 

[Not Clowning Around]

Apologies I thought I uploaded them

 

[_Jake_Simek_]

Apologies I thought I uploaded them

Are they hard? Like brittle if you try to take them off? If so it looks like a massive amount of tiny feather dusters or some other type of worm. I had a very similar growth in my tank and got a small feather duster from it. If that is the case it is nothing to alarmed about. They are super common and since you have live rock it wouldn't surprise me.

 

[Not Clowning Around]

Thank you they seem to be hard I can't brush them off and are not slimy. Just don't want an infection of anything nefarious.

 

[_Jake_Simek_]

Thank you they seem to be hard I can't brush them off and are not slimy. Just don't want an infection of anything nefarious.

I would defiantly see if another person can give their hand at this as well but im pretty certain its just a bunch of those feather dusters, they cause no harm, infract they are great filter feeders and kinda neat to look at. 99% percent of those won't grow up. You can see in this photo a feather duster and in the top right corner a juvenile one. The link to the entire article is here - http://reefkeeping.com/issues/2003-05/rs/

 

[Not Clowning Around]

Thank you so much that is super helpful. Yes if anyone else has another opinion or agrees that would be great to know!