The Water Exchange (thewaterexchange.net) sells carbon and KDF® water filters that are recommended by Dr. Andrew Weil in his book “Eight Weeks to Optimum Health.” He also recommends using a KDF® shower filter stating, “the effects of chlorinated water may include an increased risk of cancer.” The Water Exchange stocks single chlorine filters, dual and triple housing KDF® fluoride filters, chlorine whole house filters, shower filters and refrigerator filters to remove a variety of contaminants including fluoride, chlorine, bacteria, arsenic, heavy metals (lead, mercury, cadmium), iron, hydrogen sulfide, TTHMs, MTBEs, Haloacetic Acids–HAA5, VOCs, chloramines, sodium, nitrate, microorganisms and scale. They specalize in municipal filtration using KDF® media (made of copper and zinc) granulated activated carbon (GAC) built in the USA. GAC will remove organic materials VOCs and radon gas by a process called adsorption. Their Doulton ceramic sterasyl cartridges remove bacteria, sediment and cyst. KDF® removes metals, pesticides, Trihalomethanes THMs, MTBE, and neutralizes chlorine. KDF® combined with carbon (GAC or carbon block) extends the life by protecting against bacteria growth. Most systems use carbon to remove chlorine, but need replacing every 3 to 6 months — bacteria will grow in carbon. But, the copper zinc in KDF® produces zinc oxide which inhibits bacteria growth extends the life to 3 years. See NSF-53 test data.