First time hot tub owner. Just refilled a week ago, FC goes from 2-3ppm when added to zero, PH keeps rising within 24 hours. Pool store found high phosphates in hot tub and tap water. Rinsed filter, adjusted PH, added chlorine (sodium hypochlorite ), then added phosphate remover per directions, which stated 32oz per 10k gals, which would be 1oz per 312.5 gals, correct? Hot tub is 330gal, added accordingly. 24 hours later, no FC, PH higher (7.4 up to 7.8), and phosphate level coming up the same dark blue in a pillow test. Using Taylor test kit for tests. What am I doing wrong, or should I wait longer for phosphate remover to work? Water has been crystal clear since fresh fill, I refilled it originally because it got cloudy. Purged with Ahhsome before refill. Need some advice or answers, getting frustrated! At present PH 7.7, TA 60, CH 150, CYA below 30.