The Stain Drop All Purpose XpH phos-free-stain remover is a powerful product formulated to prevent and remove stains, discoloration and scale caused by metals and minerals. It is highly chlorine tolerant and works in a wide pH range, making it ideal for pool openings. When used according to directions, the product is safe and compatible with all pool surfaces and sanitizing systems, including salt pools. Available in one quart, five gallon and 55 gallon sizes for all commercial pool applications. | (800) 333-0400