Q2 What is the difference between reverse osmosis and a regular water filter?

There are two major differences between reverse osmosis and filtration:

  1. Ordinary water filters physically screen dirt and sediment particles from the water down to about one micron but do not remove dissolved chemicals. Reverse osmosis uses a polymer membrane that filters down to the molecular level, removing dissolved chemicals and salts that a regular filter cannot remove.
  2. With a regular filter, all the water flows through the filter and the particles collect in the filter or on its surface, eventually plugging the filter. In RO filtration, instead of all the water flowing through the membrane, the feed water flows across the surface of the membrane. Pure water goes through the membrane, and as some of the remaining feed water flows across the surface of the membrane, it washes impurities away from the surface of the membrane, and out to the drain. This keeps the surface of the RO membrane continuously free from contaminants. This greatly extends the lifetime of the RO membrane and insures the purity of the filtered water.