Granulated activated carbon (GAC). GAC is universally recognized and widely used as an effective adsorbent for a wide variety of organic contaminants, such as chlorine (99.9%), chemicals linked to cancer (THM's, benzine) pesticides, herbicides, insecticides, volatile organic compounds (VOC's),  PCB's, MTBE's and hundreds of other chemical contaminants that may be present in water, bad taste, and odors from your drinking water.

Carbon is extremely porous and provides a large surface area for contaminants to collect. Carbon-only filters must also use their capacity for chlorine removal, resulting in a shortened life. They also may use a bituminous coal carbon, which is good at removing chlorine, but not as effective at removing chemicals. Crystal Quest uses a high-grade coconut shell carbon that is most effective at removing chemicals. Coconut shell carbon provides a significantly higher volume of micro-pores than either coal, wood or lignite based carbon. As a result, it is more effective than other carbon types in removing trihalomethanes (THM's) and other chemicals from municipally supplied water. Since their REDOX media removes the chlorine before it reaches the carbon, the carbon capacity is not wasted on chlorine and is free to concentrate more effectively on organic contaminants.