In chemical and biological laboratories, as well as industry, cheaper alternatives such asdeionized waterare preferred over distilled water. However, if these alternatives are not sufficiently pure, distilled water is used. Where exceptionally high purity water is required,double distilled wateris used.
Distilled water is also commonly used to top offlead acid batteriesused in cars and trucks. The presence of otherionscommonly found in tap water will cause a drastic reduction in an automobile's battery lifespan.
Distilled water is preferable to tap water for use in automotive cooling systems. The minerals and ions typically found in tap water can be corrosive to internal engine components, and can cause a more rapid depletion of the anti-corrosion additives found in mostantifreezeformulations.[
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