In stage 1
, water flows through pre and post five - micron filter pads (1 micron equals 1/25,000th of an inch), which remove suspended particles such as silt, sediment, cyst (Giardia, Cryptosporidium), sand, rust, dirt, and other un-dissolved matter.*In Stage 2
, water flows through a bed of media made of a special high-purity alloy blend of two dissimilar metals - copper and zinc (KDF-55D ®, and KDF-85D). KDF is a major advancement in water treatment technology that works on the electro-chemical and spontaneous-oxidation-reduction (REDOX) principles. Chlorine is instantaneously and almost inexhaustibly oxidized.
Tests on KDF/GAC cartridge have shown 99+% chlorine removal past 20,000 gallons of water. In comparison, carbon cartridges of comparable volumes drop below 90% effectiveness after only 4,000 gallons.Click here for test data on the GAC/KDF cartridge.
Iron and hydrogen sulfide are oxidized into insoluble matter and attach to the surface of the media. Heavy metals such as lead, mercury, copper, nickel, chromium, cadmium, aluminum, and other dissolved metals are removed from the water by the electrochemical process. They are attracted to the surface of the media, much like a magnet. The media inhibits bacterial growth throughout the entire unit. In fact, it has been shown to be reduced up to 90%, eliminating the need for silver, which is commonly used in carbon-only filters (silver is considered a pesticide by the EPA and, as such, must be registered with them).
Is copper or zinc added to the water in any significant amount? No! On 2.3 ppm chlorinated water, <0.05 mg/l copper and only 0.46 mg/l zinc were measured. The EPA aesthetic levels are 1.0 mg/l for copper and 5.0 mg/l for zinc. Both zinc and copper are essential minerals for good health - the FDA recommends a daily intake of 15 mg of zinc and 2 mg of copper. Click here for more information on KDF filtration. In stage 3
, water flows through 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 causing bad taste and odor.
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. We use 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 our 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. Click here for more information on GAC filtration. In stage 4
, water flows through another five-micron filtration pad for further reduction of undesirable particles. The end result is total elimination or great reduction of a wide variety of contaminants.