Deionized Water

Deionized water (DI water or de-ionized water; also spelled deionised water, see spelling differences) is water that lacks ions, such as cations from sodium, calcium, iron, copper and anions such as chloride and bromide. This means it has been purified from all other ions except H₃O⁺ and OH⁻, but it may still contain other non-ionic types of impurities such as organic compounds. This type of water is produced using an ion exchange process. Deionized water is similar to distilled water, in that it is useful for scientific experiments where the presence of impurities may be undesirable.
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water from which the majority of ions have been removed. Tap water has resistivity of <50 kiloohms, deionized water may have resistivity as >18 megaohms. The term deionized water has been largely replaced by ultrapure water to indicate that more than just low ions counts are required.