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Individual Filter Descriptions
for Point Of Entry (P.O.E.) Filters
All filters used are certified by the National Sanitation Foundation
KDF® Process Media — Redox Treatment
Stage 1 (Tahoe & Emerald)
In this stage of our filter systems granulated pieces of copper and zinc-based alloys act as redox (chemical reduction/oxidation) agents to combine with chemicals such as free chlorine, heavy metals, and bacteria transforming them from toxic to benign compounds. Heavy metals plate out immediately on the metal granules. Others are converted, such as chlorine becoming chloride, and then stripped from the water as the final stage carbon block absorbs them.
To improve performance, the KDF® Process Media is fluidized by an upward flow of water to continually agitate it and actively improve the redox process while extending its useful life to four years.
Filter life: 600,000 gallons of water, or four years.
Pleated Absolute Filter
Stage 2 (Tahoe & Emerald),
Stage 1 (Cascade)
In this filter, a pleated membrane of polypropylene acts as an absolute 1.0 µm barrier. This removes 99% of parasites like Giardia and Cryptosporidium and most bacteria. Very fine particles are also blocked, reducing turbidity and protecting the carbon block from fouling which improves their performance as well.
Many popular blocking filters rate their porosity in nominal terms. Thus particles with a slightly larger dimension can and do pass through. With absolute ratings only particles less than or equal to the size rating are allowed to pass.
Filter life: 1 year or when pressure drops.
Coconut Shell Carbon Block
Stage 3 (Tahoe & Emerald),
Stage 2 (Cascade)
Carbon as a filter media is the workhorse of water filtration systems. It eliminates the taste and odors of chlorine and disinfection by-products, while adding nothing to the water itself. We use the highest rated, NSF Certified coconut carbon filters in the world. The common alternative, granular activated carbon (GAC) is derived from coal which has a lower absorption value. Part of this is the result of the granules propensity to shift under the pressure of flowing water, creating channels with lower resistance and thus, less contact time and lower absorption rates. By comparions, coconut carbon has a rigid structure to force an even flow of water throughout its available surface area. As a result, more impurities bond to coconut carbon resulting in filtration that is far superior to GAC filters.
This is the common last stage in our whole house systems, with a nominal porosity of 0.5 µm. It reduces chlorine, chloramines, disinfection by-products, pharmaceuticals, organic chemicals, as well as their taste and odors.
With our Tahoe POE system we use two stages of coconut carbon to maximize filtration and enhance purity. Stage 3 has a nominal porosity of 1 micron, which adsorbs impurities and acts as a prefilter to the half micron porosity of Stage 4.
Filter Life: 140,000 gallons, approximately one year, or before taste and odor appear.