Check the listing for details. Natural Chemistry Spa Stain & Scale 16oz.. Condition: New. Listed at 17.99 USD. Stain and Scale Control​ protects spas from the damaging effects of scale buildup and staining due to excessive calcium, iron, copper, and other minerals. It works without the use of phosphates or harsh acids. Spa Stain and Scale​ also works to prevent scale from forming on salt generator cells to help maintain optimum performance. Directions: Initial Treatment of Fresh Fill:​ Add 8oz per 200 gallons directly to spa water. Weekly Maintenance:​ Add 1 oz per 200 gallons directly to spa water. Note:​ If the water hardness level is above 400 ppm, double the weekly maintenance dosage. Do not exceed the recommended dose 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.