WHY DOES THE PURIFIED WATER NEED TO BE REMINERALIZED WHEN BEING SUPPLIED FOR POTABLE WATER USE?
All natural water contains a small amount of dissolved carbon dioxide. Gasses readily pass through semi-permeable membranes and when water is processed by reverse osmosis, the carbon dioxide passes through the membrane with the purified water. Since most of the alkalinity (natural pH buffering ions dissolved in tap water) are removed by the reverse osmosis process, the excess carbon dioxide causes the pH of the purified water to become acidic (low pH). Acidic water, especially water containing a low amount of dissolved ions, like reverse osmosis water, will tend to corrode and dissolve metallic piping components. When reverse osmosis water is used in typical domestic water piping systems composed of copper or iron piping materials, it is wise to temper the aggressive nature of the purified water so that the piping systems’ integrity can be maintained and so that excess dissolved metals do not end up in water being used for drinking. It is also commonly desired to replace a small amount of “good” mineral into the purified water in order to improve the palatability of the water for drinking and to aid in soap removal during washing and bathing. In order to correct the purified water chemistry, the HydroMax system uses calcite (crushed, pure limestone) filtration media to neutralize the excess carbon dioxide and raise the pH of the purified water. The calcite media dissolves very slowly in the purified water flowing through the remineralization filters, releasing a small amount of calcium. Fresh calcite media will need to be added to the remineralization filters periodically to replace that which dissolves. Potable water can also require a chemical addition in order to increase the pH and alkalinity of the purified water in order to help prevent water distribution system component and piping corrosion.