If you think it is green turf algae, have you taken the recommended steps described by ReefCleaners?
“What is known as "Green Turf Algae" in the hobby is really a generic name given to hundreds of different species of macroalgae that describe certain similar characteristics. They are coarse, wiry, and generally have thicker wider blades than Green Hair Algae. They may or may not have a mat like root structure, sometimes they just seem to sprout from the rock.”
“Turf algae that sprouts directly from the rock can be a pain to control, as it is difficult if not impossible to pluck it all. Once discovered it should be treated outside of the aquarium, perhaps by dipping the affected rock or frag in water treated with an algaecide.Turf algae that grows with a "root" mat can be peeled by pushing down on the algae as you scrape your thumb against the rock dislodging it in one swoop. Let it get big enough so you have leverage. The 3reef member who removed this piece did it perfectly.”
“Clean up Crew members that will eat Green Turf Algae include inverts with considerable cutting power like urchins, chitons, and emerald crabs.”
I have already asked you some relevant questions to identify the algae. Until you provide more data, I can not guess the answer.
In reviewing some of your threads, I see no tank thread that has your system set up or chemical parameters. It would help if you at least indicated basic tank parameters like nitrate & phosphate. How long has tank been set up. Any dosing for alkalinity? Carbon dosing? Chemical filtration?
