My pool is free form, 36ft long and 24 ft at its widest and 16 ft at its thinnest. It holds 20,000 gallons as it is 3.5ftx5ftx4ft on the depth. It has a SWG and Tahoe Blue Pebble Tec. I would really like to get the phosphates down. Will multiple treatments of PhosFree work? I know it is expensive but I do not want to floc if I do not have to.