This powerful formula is specially designed to bond with troublesome metal ions in your spa water, filtering them out and eliminating scale buildup that can cause cloudy water and clog up filters. Say goodbye to unsightly stains caused by metals and prevent damage to your spa surface and circulation system with this effective product. With its powerful agents that bond to problem-causing calcium ions in your spa water, SpaGuard Stain and Scale Control prevents scale formation and removes some scale buildup on spa surfaces. It also effectively removes relatively fresh metal stains from your spa surfaces, leaving your spa looking clean and inviting. Keep your spa water crystal clear and your spa in pristine condition with SpaGuard Stain and Scale Control.