Distilled water

Distilled water is water that has been boiled into vapor and condensed back into liquid in a separate container. Impurities in the original water that do not boil below or near the boiling point of water remain in the original container. Thus, distilled water is one type of purified water. Distilled water is water that has been boiled into vapor and condensed back into liquid in a separate container. Impurities in the original water that do not boil below or near the boiling point of water remain in the original container. Thus, distilled water is one type of purified water. Drinking water has been distilled from sea water since at least about AD 200, when the process was clearly described by Alexander of Aphrodisias. Its history predates this, as a passage in Aristotle's Meteorologica (II.3, 358b16) refers to the distillation of water. Captain Israel Williams of the Friendship (1797) improvised a way to distill water, which he described in his journal. In chemical and biological laboratories, as well as in industry, cheaper alternatives such as deionised water are preferred to distilled water. But if these alternatives are not pure enough, distilled water is used. If exceptionally high-purity water is required, double distilled water is used. In general, non-purified water could cause or interfere with chemical reactions as well as leave mineral deposits after boiling away. One method of removing impurities from water and other fluids is distillation. For example, ions commonly found in tap water would drastically reduce lifespans of lead–acid batteries used in cars and trucks. These ions are not acceptable in automotive cooling systems because they corrode internal engine components and deplete typical antifreeze anti-corrosion additives. Any non-volatile or mineral components in water are left behind when the water evaporates or boils away. Water escaping as steam, for example from a boiler of heating system or steam engine, leaves behind any dissolved materials leading to mineral deposits known as boiler scale. Low-volume humidifiers such as cigar humidors can use distilled water to avoid mineral deposits. Certain biological applications require controlled impurities, especially in experiments. For example, distilling water to be added to an aquarium would remove known and unknown non-volatile contaminates. Living things require specific minerals; adding distilled water to an ecosystem, such as an aquarium, would reduce the concentration of these minerals. Fish and other living things that have evolved to survive in lakes and oceans should be expected to thrive at mineral ranges found in their original habitat. Controlled impurities as well as equipment reliability are critically important in medical applications where, for example, distilled water is used in Constant Positive Airway Pressure (CPAP) machines to humidify air for breathing. Distilled water will not leave contaminants behind when the humidifier in the CPAP machine evaporates the water.