The CuLator CUL-ULT-1 Metal Eliminator and Stain Preventer Ultra PowerPack 4.0 is a monthly maintenance kit that helps eliminate the metal from your water using non-toxic alternative sanitizing methods. Simply add one monthly dose to your pool and immediately start repeating the results of smoother and cleaner pool water. The Metal Eliminator and Stain Preventer Spring Opening PowerPack removes copper, iron, manganese, colbalt, nickel, and silver within your fresh or salt water pool using a non-toxic, easy to use mix without phosphates.