Whole House Water Filters

by Trent Barrett

A reverse osmosis water filter works by allowing water to pass through a thin membrane that does not allow other materials to pass. This means you wind up with clean, pure water on the using side of the membrane, while heavy metals, biological contaminants, and even chlorine remain on the other side of the membrane, filtering out and eventually flushed from the water filter’s system. A reverse osmosis water filter eliminates almost all of several contaminants from your drinking water: arsenic, chlorine, fluoride, heavy metals, nitrates, sediments, iron, bacteria, viruses, bad tastes and odors, and some of your hydrogen sulfide and VOCs (an example: pesticides).

The reverse osmosis water filter is also referred to as a hyperfiltration system. That’s because it is so very effective at removing contaminants from your water supply. It works by moving your water through a series of reservoirs, in which the clean water moves to the clean side of the filter, leaving behind the contaminants. The filter does not work through pressure; instead, water must move passively. This means that the filtration process is slower than you might find in other water filtration systems. A reverse osmosis water filtration system will require a large tank to be installed under your counter which will provide a drinking water reservoir. In most systems, you can expect to produce around fifteen gallons a day of bottled-quality water. If you’re a bottled water fan, this will save you much more than the reverse osmosis filter will cost you.

A reverse osmosis water filter may have a thin film composite (TFC) or a cellulose triacetate (CTA) membrane, each of which has strengths and weaknesses. The TFC is best by far at contaminant removal, but it is easily damaged if you have a chlorinated water supply going directly into it. For TFC filters, it’s a good idea to install an activated carbon filter upstream of the TFC filter. The CTA filter is not as good at removing contaminants, but it is also tougher and will not be so easily damaged. Because a damaged film can ruin your reverse osmosis water filter, choose carefully between these two options.

For water that is contaminated with bacteria or other biological organisms, you may also need an ultraviolet filter. While an osmotic filter works quite well on biological organisms, it does not catch all of them; while one particle of mercury in your cleansed water will not kill you, a single bacterium in your clean water reservoir can multiply and eventually contaminate your entire osmotic water filtration system. To prevent this problem, add a UV water purifier to the downstream side of your filtration system. UV light is used to kill everything living in your water, which prevents your water from further contamination. This three-filter system - activated carbon, reverse osmosis, and UV purifier - will provide you and your family with the cleanest possible water supply.

Your last concern with a reverse osmosis water filtration system: the amount of water used in producing your clean water. Each one gallon of clean water requires up to ten gallons of water, the remainder of which is flushed from the system. If this is a problem in your area, make sure that your contaminated water is redirected to your gray water reservoir, where it can be safely used to water your garden.

About the Author:

Trent Barrett is a consultant who writes for Best-Home-water-Purifiers.com. You can visit their homepage to learn more about Home water Purifiers.