Jack's Magic's The Copper & Scale Stuff Stain Solution 2 provides pool owners with an easy and effective way to remove copper stains and scale buildup, while being more effective than acid-washing your pool. Stain Solution 2's powerful formula cuts through stains and scale, yet is compatible with all pool types and surfaces. This solution will save you time by eliminating hand scrubbing or pool drainage from your maintenance list, yet will be just as effective. In order to use this product safely, you must be able to bypass your heater. Product Dosage 10 lb per 10,000 gallons of water.