About Reverse Osmosis

Reverse Osmosis (RO) is a water purification process that uses pressure to force water molecules through a semipermeable membrane to remove impurities and contaminants. The 0.0001 micron* pores (holes) in the membrane prevent the larger molecules of dissolved impurities from passing through with the smaller water molecules. The result is clean, high quality drinking water.
reverse-osmosis-diagram
*A micron is a unit of length, for example most bacterial cells range from 0.2 to 1 micron in width. Filters with "nominal" pore size have an average pore size of the micron size listed, which means that some of the pores are smaller or larger than the listed micron size. Please note that this image is not to scale.

What can reverse osmosis remove from drinking water?

According to the CDC, reverse osmosis will remove protozoa, bacteria, viruses and common chemical contaminants from drinking water:
  • Reverse Osmosis Systems have a very high effectiveness in removing protozoa (for example, Cryptosporidium, Giardia);
  • Reverse Osmosis Systems have a very high effectiveness in removing bacteria (for example, Campylobacter, Salmonella, Shigella, E. coli);
  • Reverse Osmosis Systems have a very high effectiveness in removing viruses (for example, Enteric, Hepatitis A, Norovirus, Rotavirus);
  • Reverse Osmosis Systems will remove common chemical contaminants (metal ions, aqueous salts), including sodium, chloride, copper, chromium, and lead; may reduce arsenic, fluoride, radium, sulfate, calcium, magnesium, potassium, nitrate, and phosphorous.

5 Stages of Filtration

Each Olympia reverse osmosis system includes these 5 stages of filtration: 5 micron sediment filter (stage 1), 5 micron carbon block filters (stages 2 & 3), reverse osmosis membrane (stage 4) and post-carbon filter (stage 5). As shown in the diagram below, these 5 stages of filtration purify tap water and well water to provide clean, high-quality drinking water.
Olympia-RO-System-Flow
  1. Sediment Filter

    5 micron polypropylene sediment filter removes sand, silt, dirt and rust particles.
  2. Carbon Block Filter

    5 micron coconut shell carbon block filter removes volatile organic carbon compounds, insecticides/pesticides and chemicals.*
  3. Carbon Block Filter

    5 micron coconut shell carbon block filter removes volatile organic carbon compounds, insecticides/pesticides and chemicals.*
  4. Reverse Osmosis Membrane

    Removes the following contaminants: Arsenic, Barium, Cadmium, Chromium (Hexavelent & Trivalent), Copper, Turbidity, Fluoride, Lead, Radium 226/228, Selenium* & TDS.
  5. Post Carbon Filter

    Coconut shell post carbon filter reduces chlorine, taste & odor.
*These claims are based on manufacturer testing. These claims are not certified by NSF.