This pic is under blues thru orange lense during the day this looks black will post follow up pic when day lights are on. It looks like hair algae but stays short and doesn’t easily come of rock a tooth brush barely touches it. Any ideas what it is?
Had something like that, scrubbed with a toothbrush had little effect.
I put one Mexican Turbo on each affected rock. Gone to 2 weeks.
I did keep redirecting him on rocks.
