In simple terms, reverse osmosis is the process by which water molecules are forced through a semi-permeable membrane under pressure. Reverse osmosis systems provide filtered water everywhere, from homes and commercial applications like restaurants and hotels, to breweries and car washes, and even the space shuttle!

Household RO systems typically filter water using the following steps:

1. Raw tap water first flows through a sediment filter to remove dirt, rust and other solid objects.
2. The water then flows into a carbon filter that takes out 98% of the chlorine and organic chemicals.
3. The next stage is the reverse osmosis membrane which separates 70-99% of the dissolved contaminants from the water molecules. These removed impurities are rinsed down the drain producing the final product, “pure water”.
4. This water is stored in a reservoir tank typically located underneath the kitchen sink and is accessed with a separate faucet.
5. When you open the valve the water is filtered one last time with a carbon block “polishing filter” right before it reaches your glass.

Using a quality RO membrane as a strainer is typically much better than a faucet mounted filter alone. Under magnification the pores of a RO membrane are undetectable, while the pores of a pleated filter are easily seen. Reverse osmosis treatment generally removes a more diverse list of contaminants than other systems. RO can remove nitrates, sodium, and other dissolved inorganic and organic compounds.