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.
If you have a problem with biological contaminants, you should consider using not just a reverse osmosis water filter by itself, but also using an ultraviolet filter, as this filter is the most effective by far in removing biological contaminants without otherwise contaminating your water supply. So your perfect reverse osmosis water filter may need to have a total of three filters to be completely effective at cleaning your water: the activated carbon filter (which needs to be changed regularly), the osmosis filter, and the ultraviolet filter (which needs an electrical power outlet). With these three filters in your system, however, you can be assured of a tasty, reliable, and clean water supply for your home and family.
The only other thing you may need to be concerned about with a reverse osmosis water filtration system is the amount of water it takes to create those fifteen gallons a day - up to ten gallons for each gallon of clean water created. If you live in an area where water needs to be conserved, you may need to ensure that rejected water goes into your gray water reservoir, where it can be used to feed your flowers.
