just above my water line, i have some build up of white scale which i believe is calcium on my pebble tec. on that build up i have black splotches that turn bright green when the chlorine dips a bit. then i typically raise the water line to cover the green then boost the chlorine.
i was told this was black algae at my neighborhood pool store. it was recommended i let the water line drop then attack the build up with a pumice stone to remove the build up and ultimately the black algae.
just wanted to get a 2nd opinion on the best way to remove the build up and also the black algae?