Ionized water and distilled water are fundamentally different forms of treated water, created by separate processes to achieve distinct chemical compositions and intended purposes. Distilled water is a highly purified form of H₂O, stripped of its mineral content. Ionized water is filtered water that has been electrically altered to change its acidity and concentrate its dissolved minerals. These differences in production and resulting chemical properties make them unsuitable for interchangeable use.
The Process of Distillation
Distilled water is produced through a process that mimics the natural hydrologic cycle of evaporation and condensation. The method begins by heating source water to its boiling point of 212°F (100°C), causing it to vaporize into steam. This intense heat kills most bacteria and viruses while leaving behind virtually all non-volatile impurities, including heavy metals, salts, and minerals. The resulting pure steam is then directed into a cooled chamber called a condenser, where it reverts to its liquid state, forming the distillate. This process yields water that is nearly 100% H₂O with a Total Dissolved Solids (TDS) measurement close to zero, achieving an extremely high level of purity.
The Process of Ionization
Water ionization relies on electrolysis, typically performed by a specialized water ionizer machine. Source water must first be filtered to remove contaminants, as ionization is not primarily a purification method. The filtered water then passes over electrically charged plates inside an electrolysis chamber. The electrical current separates the water molecules and dissolved minerals into two distinct streams: alkaline and acidic. The alkaline stream contains a higher concentration of hydroxide ions (\(\text{OH}^-\)) and alkaline minerals, while the acidic stream contains a higher concentration of hydrogen ions (\(\text{H}^+\)) and acidic minerals. Ionization uses an electrical charge to redistribute the existing mineral content and alter the water’s pH balance, rather than removing the minerals entirely.
Comparing pH and Mineral Content
The chemical profiles of distilled water and ionized water represent the most significant point of difference. Distilled water, being nearly pure \(\text{H}_2\text{O}\) with no dissolved solids, is chemically neutral upon creation, possessing a \(\text{pH}\) of approximately 7.0 and a Total Dissolved Solids (TDS) reading often below 5 parts per million (ppm). This mineral-free state makes the water highly unstable and capable of absorbing carbon dioxide from the air quickly, which can cause its \(\text{pH}\) to drop slightly. In contrast, the alkaline stream of ionized water is substantially basic, commonly exhibiting a \(\text{pH}\) that ranges from 8.5 to 10.0. This higher \(\text{pH}\) results from concentrating alkaline minerals like calcium and magnesium from the source water, meaning its TDS level remains significant.
Intended Uses and Consumer Context
The distinct chemical natures of these two water types dictate their practical applications, confirming they are not interchangeable. Distilled water is preferred where the absence of minerals is paramount to prevent residue or interference. Common uses include medical devices like Continuous Positive Airway Pressure (CPAP) machines, steam irons, laboratory experiments, and topping off car batteries, where mineral-free water prevents the buildup of scale and mineral deposits. Ionized water, specifically the alkaline stream, is primarily marketed as a consumer beverage for daily hydration due to its higher \(\text{pH}\) and retained mineral content. The acidic stream produced by the ionizer is not for drinking but finds use in topical applications, such as a skin toner or general-purpose cleaner.