I would not restart. How big is the tank? Agree with post above that at least it's not Dinoflagellates. Although you have been battling for 8 months, it really does take over 1 year to stabilize a tank. I don't really see a significant GHA problem based on your pictures. I would go back to the basics. Make sure your water source is 0 TDS and there are no contaminants. Do you use RO/DI? Have you changed out your filters? What do you feed? Pellet/flake food may have more phosphates. How much do you feed? How much water changes do you do? Do you use a skimmer? Is it sized correctly? Do you have macroalgae? GFO? How much lighting do you have on your reef? How many hours? What kind of clean up crew do you use? I really find Astrea and Turbo snails very effective in removing hair algae. I'm not a proponent for additives or needless medications as above measures are usually enough with patience as the tank matures. If you have bryopsis though ultimately fluconazole can be helpful. Good luck.
