Is Deionised Water the Same as Distilled Water?

Is Deionised Water the Same as Distilled-Water

No, these are two different kinds of water. The difference between deionised and distilled water is how they’re produced and the output water’s quality. Both produce pure water but differ in their purity. Purified water is needed for a broad range of uses including home, medical, and industrial use.

The type of purification to select will depend on what properties are needed for the intended use, so it’s necessary to learn the difference between the two.

Production of Deionised and Distilled Water

What is deionised water? Deionised water has been stripped of inorganic compounds like salts and other types of minerals. In order to achieve this, the water passes through special resins that contain anions and cations, which allow for the capture of atoms that are oppositely charged.

This results in pure water with non-ionised molecules. The process is effective in removing nearly all inorganic contaminants. However, the water has to be filtered with a different media before deionisation for the removal of organic compounds.

Distilled water, on the other hand, makes use of condensation, evaporation, and heat for the removal of both inorganic and organic compounds. The distillation of water involves the heating of contaminated water until it becomes steam from evaporation. The steam is captured in a hood or sterile container overhead where it is condensed back into water. It’s shunted to a different container.

Although distillation and deionisation remove inorganic contaminants, organic material is removed from distillation and requires no extra filter.

Uses and Applications of Deionised Water

Deionised water is primarily used for medical, industrial, and laboratory processes. Human consumption or home use is possible, but it’s less common. Deionised water is more ideal for atomizers and injection systems where regular water leaves behind particulate matter buildup that clogs nozzles which hamper equipment performance over time.

It’s also used where sterile or biological fields are required. In cases where there’s electrical conduction and it has to be reduced, the balanced ions in deionised water can be useful. You’re probably wondering where to buy deionised water. For most medical and industrial uses, cartridge-based systems are installed with the water supply of a building for on-site production.

Uses and Applications of Distilled Water

Distilled water also has industrial, medical, and laboratory uses. However, it’s often used within homes in comparison to deionised water. Regular water contains alkalis, acids, and other minerals which affect food’s colour and taste.

The distillation process reliably removes viruses, bacteria, and heavy metals in water such as mercury, arsenic, and lead. That being said, distilled water is safer for human consumption. It’s also for medical processes that require hyper-vigilance with organic materials when sterilising equipment and instruments.


Deionised and distilled water differ in their production and the type of contaminants that are removed. Both have many uses as mentioned in this article. While they’re interchangeable for some applications, the material that’s removed is a factor to consider when choosing the kind of water to use.