I have a FC of 3 and CYA 0f 50-60 salt is about 3150 ppm and it's been hot here so we left the solar cover off. We have a buildup of a green powder around the floor circumference -- it isn't attached and easily sweeps away like talcum powder. I was able to vacuum it and the pool water is clear. I thought it was algae but my wife claims algae will attach to the walls and floor. Also thought it might be pollen (like that which covers my BBQ grill). I also put DE in my sand filter before I vacuumed since it looked real fine particles.
Not sure if I should shock or not. Is there a way to be sure?