Check the listing for details. Natural Chemistry Spa Alkalinity Increaser 2.71Ib.. Condition: New. Listed at 33.99 USD. Natural Chemistry’s Spa Alkalinity Increaser​ is used to raise total alkalinity in spa water. Total alkalinity in spa water should be maintained between 80-120 ppm. As a result of the buffering effect of total alkalinity, pH, bather comfort, water balance, and clarity are more easily maintained. Directions: Test spa water for total alkalinity level. Compare test results to the chart below to determine the appropriate amount of product necessary to adjust. With the spa circulating pump at high speed, add the required amount directly into the spa water. Continue circulating water for a minimum of 20 minutes. Spa Volume 20ppm 40ppm 80ppm 100ppm 200gal 1oz 2oz 4oz 5oz 400gal 2oz 4oz 8oz 10oz 800gal 4oz 8oz 16oz 5oz SHIPPING: We will do our best to ship your order based on the shipping method selected, however in some cases, your shipping method may need to be modified to meet shipping requirements based on the carrier. Our current carriers used are UPS, FedEx and USPS. Please contact us directly through the "Contact Seller" link if you need UPS, FedEx or USPS specifically for your order.