2-Pack Control the pH - perfect balance for hot tub spa - 2 x 32 oz. bottles (64 oz. total)
Control the pH eliminates fluctuating pH. Use only one dose each time the spa is filled. This product was developed to help maintain and balance pH in your spa or hot tub. Lasts until spa is drained and refilled (approx. 2 to 4 months.)  Enough for 500 gallons.  Reduces maintenance time and adjustment chemical usage. Product notes: Add after adjusting your spa's Total Alkalinity and pH.  Control the pH begins working immediately to lock pH of the spa into the appropriate range.  Guraranteed to equal or outperform Leisure Time pH Balance, pH Hold, pH Proper and Robarb Perfect pH. Not recommended for use with hard water. Not compatible with biguanides such as Baqua Spa.