Pacifi Clear F066001012PC 1 Quart Metal Out Plus Features : Ideal for basic pool careEffective rust-control agentRemoves established metal stains and depositsHelps reduce scale caused from metals and minerals alikeChelates metals and minerals to prevent them from falling out and therefore staining1 quartSoluble metals can be inhibited from precipitation by sequestering/chelating agents that bind with the colored metal ion to keep it in solution. Metal Out Plus sequesters the material causing stains and scale and holds them in solution. Regular use of this product helps keep pool water clear, the pool walls free of stains and prevent corrosion of metal pool fittings. Use of Metal Out Plus as part of the pool maintenance program will result not only in the control of scale, but also in the removal of existing deposits. This product is also highly effective as a rust-control agent.