What is Reverse Osmosis

WHAT IS REVERSE OSMOSIS?

Reverse osmosis is the most convenient and effective method of water filtration. Often referred to as RO, is an advanced water purification method. It was initially developed by the U.S. Navy to produce drinking water from sea water for submarine crews.

It is a membrane filtration technology that works by forcing water under pressure through the very tiny pores of a semi-permeable membrane. Modern reverse osmosis units for the home combine membrane technology with carbon and mechanical filtration to produce highly purified, great-tasting water.


HOW DOES IT WORK?
Simplified Version:

Water is driven by city water pressure.

1) It flows first through a through a sediment filter where silt, sediment and particles (like sand and clay) are removed. It protects the automatic shut-off and the membrane from clogging with debris.

Then water flows through two types of Carbon Pre-Filters, which removes organic contaminants including chlorine and its by-products.

2) Catalytic Carbon Pre Filter is specific to Chloramines. This is how Bay Area disinfects water.

3) Granular Activated Carbon Pre Filter for Chlorine and other chemical contaminates such as pesticides. Some Units will have a Fluoride Filter instead.

4) Next, it enters the reverse osmosis membrane, a very tight, sheet-like filter, that allows water to pass but rejects dissolved solids like sodium and impurities like lead and arsenic. Some of the water entering the unit is used to cleanse the membrane surface and flows to the the kitchen drain pipes.

The purified water is stored in a small storage tank until it is needed.

5) When the RO faucet is opened, the purified water is forced by air pressure through another carbon filter, which gives it a final polish and from there to the RO faucet.

6) Final Stage, water flows around the ceramic beads were trace amounts of minerals are returned to the water. This creates naturally alkaline water with slightly negative charge.

Note: The simplified description omits a few very essential parts like flow control devices, check valves, and an automatic shutoff devices that stops the inflow of water when the storage tank is full.

IS A REVERSE OSMOSIS UNIT LIKE A DISTILLER?
Both effectively reduce “dissolved solids” content of water, but the processes are quite different.

RO filters water through a very tight semi-permeable membrane. A distiller is like a big tea kettle: it boils water, catches the steam, condenses it, and captures the resulting water. Most impurities are left behind in the boiling chamber.

Both distillers and reverse osmosis systems rely heavily on carbon filtration for chemical removal. (Cheap distillers often have little or no carbon filtration and are, therefore, of limited effectiveness.)

Heat from distilling liberates the energy inherent within the water. Most people don’t realize that water has energy. This energy can not be returned with a carbon filter. The healthiest water will have a negative charge.

BUT ISN’T DISTILLED WATER MORE PURE THAN REVERSE OSMOSIS WATER?
Distillers typically remove a few parts per million more of common mineral constituents like sodium.

However, distillers don’t do a good job with volatile chemicals with a low boiling point. Chloramines, for example, which many cities now use instead of chlorine as a disinfectant, are not well removed by distillers.

Reverse osmosis, with the carbon filters that accompany it, does a very good job with chloramines. Unless volatile chemicals like chlorine are removed by carbon filtration before they enter the distiller, they will be released into the room air or they will end up in the distilled water.

But in general, distilled water is very pure, as is reverse osmosis water.