What is Reverse Osmosis and How Does it Work?

Like most filtration systems, reverse osmosis works by funneling contaminated water through a semi-permeable membrane that removes a specific set of impurities. Unlike some other solutions, the system applies pressure to the water as it flows through the membrane, using the natural tendency toward chemical equilibrium to trap offending ions (like salt) in order to achieve the desired state of contaminant-free water. The membrane traps impurities, usually around .001 microns or larger, so that what exits the membrane to your faucet is purer, potable water.

Reverse osmosis technology was developed during the 1970s, and is most commonly used to desalinate water in areas where fresh drinking water may be hard to access. RO is also common in industrial applications, like our very own Culligan Reverse Osmosis, where it can be used to treat water for facilities and recycle commercial wastewater.

How does reverse osmosis work to treat my water?

Residential systems use the same pressure membrane technology to separate contaminants from municipal water, and may include additional filtration steps like sediment filtration or UV sterilization. Our residential reverse osmosis systems, for example, include pretreatment as a matter of course, and post treatment as needed. If water quality is especially concerning in your area, you'll want to make sure your RO system is used in conjunction with a sterilizing filter to ensure water is not only free from saline and other particles, but any harmful contaminants like E. coli or arsenic. These features are always included in Culligan reverse osmosis products to ensure the highest-quality result for your water.

What types of water problems does it work best for?

RO works best for water with high saline content and relatively few other impurities. Beyond salt-water fixes, reverse osmosis can also be used to remove chlorine and fluoride from drinking water, and in general, be used to remove a variety of:

  • Metals 
  • Minerals 
  • Microorganisms

It can be challenging to know exactly what type of filtration product is right for your home and your water supply. Whether you're considering reverse osmosis, or any other type of filtration, it's helpful to have your local Culligan Man test your water in order to make the best recommendation based on the unique needs of your tap.

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