PH Minus$4.00 Lowering your pH will also lower your alkalinity. The ideal pH level is between 7.5 and 7.8 ppm. PH Minus quantity Add to cart Category: Pool Chemicals Related products Add to cart Stabilizer $8.50 Add to cart Alkalinity Increaser $10.50 Add to cart PH Plus $3.75 Add to cart Carboy Shock $25.00