Reverse Osmosis Water Filtration System

A reverse osmosis water filtration system is one option for the homeowner to choose in treating problems with their drinking water. Because all systems cannot be all things the homeowner should have his water tested by a professional laboratory. Then pick the system, or systems, that will best solve his problems. Reverse osmosis is an effective method for reducing certain metals and ions. It also can remove microorganisms but is not recommended for that use.

Certain dissolved gases cannot be removed from water using this process. Nor can certain solvents, other VOC's (volatile organic compounds), or some pesticides, be removed using this type of system. These contaminants pass through the membrane of the filter and are not removed or reduced.

Reverse osmosis works by using a membrane to separate two different solutions. In this case, two different types of water; one having a higher concentration of dissolved contaminants or the incoming supply, and one having a far lower level of these problems or the treated water. The natural order of things, or osmosis, is for the cleaner water to pass to the water with the higher level of contaminants to balance the two solutions.

The desired result is achieved by applying pressure to the water on the contaminated side to push pure water through the membrane while (for lack of a better phrase) straining out the impurities in the water. The contaminants left behind in the high concentration side are then washed away. This is then, considered waste water.

For these types of systems to work the incoming supply of water must supply a certain amount of pressure to the pre-filtered side to overcome the natural osmosis process. It is a general rule that, the higher the pressure difference between the two sides of the membrane, the better it works in removing contaminants and increasing the amount of water that is recovered in relation to the amount of waste water. If the water pressure is not sufficient on its own, pumps may need to be added, to supply the pressure necessary for the system to work properly.

These systems when normally used in homes has the capability of producing a range of usable water between 15-30 gallons a day. There is no getting around the fact that a significant amount of waste water is generated by the process, sometime as high as 70 to 80 gallons wasted for every 20-30 gallons filtered. Adjustments can be made to increase the usable water and lower the waste rate, but the homeowner needs to be aware of how the process works and just how much water will end up flushed down the drain.

Of course no one method of treatment can remove all problems from your water. Because of this, it is common to find reverse osmosis filtration coupled with both a sediment pre-filter and an activated carbon filter following the unit. This type of setup will extend the useful life of the membrane by filtering out sediment which can clog the unit and reduce odors and tastes the system, by itself, cannot remove.