DeIonized Water - DI Water. DI Water - Water in its purest form consists of Hydrogen (H+) and Hydroxyl (OH-) ions, which combine to create H2O. When considering a water’s purity, anything found in water other than the Hydrogen and Hydroxyl ions, are an impurity. Bacteria, minerals, charged ions, pharmaceuticals, caffeine, fertilizers, volatile organic compounds (VOCs), cleaning agents, debris or anything else we’ve introduced into our water system, is an impurity. DI Water is Intended for industrial applications. We do recommend using the DI Water when mixing the chemicals so the cleaning effect will be much more powerful and the chemicals will last longer.