Loading... Please wait...Case of 4 one gallon bottles of muriatic acid. A $6.00 return deposit is required for this product. This product is only available for delivery in Eastvale, Norco, and Corona. Maintaining a clean and safe swimming pool requires attention to the water's chemistry. Muriatic acid is used to lower the pH factor, which affects every other chemical balance. The optimum pH range for pools is 7.4 to 7.6. Add only 1 pt. of muriatic acid to the pool at one time. Wait 4 hours after application and retest to determine if more chemical is required, and how much