Demineralized water also known as Deionized water, water that has had its mineral ions removed. Mineral ions such as cat ions of sodium, calcium, iron, copper, etc. and anions such as chloride, sulphate, nitrate, etc are common ions present in water. Deionization is a physical process which uses specially-manufactured ion exchange resins which provides ion exchange site for the replacement of the mineral salts in water with water forming H+ and OH- ions.