I manage a pool company in Florida. I’ve had several pools that turn milky white and have heavy deposits of white powder resembling “flour” on every square inch with heavier concentrations in the creases 24 hours after adding, on average , 10 pounds of alkalinity increaser along with 4 pounds of calcium increaser. I tested the backwash water for alkalinity level, tested 400 ppm, pool water tested at 120 ppm. Backwash water was pure white resembling milk. Vacuumed to waste/discharge, did a sand change and even a full filter replacement and the powder still returned. I’m at a loss, any advice would be great
