Can anyone identify this algae?
Tank is around 3 months old
Was thinking it was GHA but I’d doesn’t look anything like the pictures of the GHA I see everyone posting.
will an tuxedo urchin eat it?
Yes, green hair algae. I'm not sure a half dozen tuxedo urchins could make a dent. I think removal of the rocks into a separate container of seawater, scrubbing and then rinsing in another container of seawater is your best bet at this point.