The Heavy Metal Reduction Set will remove dangerous metals like Lead, Mercury, Nickel, Selenium, Thallium, Copper, and others. These metals have dangerous side effects to your health and the health of animals. This set is not for your entire house, but only for one faucet. Heavy Metal Cartridges need quite a bit of saturation time with water, and flow at a low rate. It filters heavy metals out 100% for 325 gallons, and the rate decreases from there upon use.