About Reverse Osmosis Water Filtration

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 reverse osmosis 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.