Help identifying this hairy growth

[Radar1721]

Can someone Id this stringy growth for me? I have two spots that recently sprouted up on a piece of live rock I've had for over a year. I recently took all of my fish out to go fallow for ich elimation. I also started dosing two part and installed an algae turf scrubber. My nitrates have always been high, but now nitrates and phosphates are basically undetectable. My corals are looking great and I think they are really starting to sprout. I'm guessing this is some kind of hitchhiker that has been there the entire time, but was not thriving. There are various mollusk type critters on the rock as well.

Thanks

 

[AlSimmons]

If your referring to that green stuff it looks like GHA or something similar IMO.

https://www.reefcleaners.org/nuisance-algae-id-guide

 

[Radar1721]

It's not gha. I have that growing on my turf scrubber. This is not green. It's a dark brown and very coarse, stringy like.

 

[AlSimmons]

Well whatever it is the remedy is probably the same as it is for GHA.

Can you post another picture of it without the blues on?