From scientific experiments to the water you put in your iron, water purity matters. Even trace impurities can throw off results or damage equipment.
Two common types of purified water are distilled water and deionized (DI) water. Both are extremely pure, but they achieve that purity in different ways.
This article will compare DI water vs distilled water, breaking down the differences, common uses, and which type of water is best for specific applications.
Distilled Water: Purification Through Boiling
Distilled water is purified through a process of boiling. The water is heated to the boiling point, and the resulting steam is collected and then cooled back into liquid form.
Distillation removes contaminants like chlorine and dissolved solids, leaving you with relatively pure H2O.
Uses of Distilled Water
Distilled water is considered safe for drinking, although some believe that drinking only distilled water over the long term may have health implications, since the distillation process also removes beneficial minerals.
Distilled water is often recommended for use in appliances like CPAP machines, humidifiers, and steam irons. It’s also used in car maintenance, in aquariums, and on houseplants.
Distilled water is often used in these applications because it doesn’t leave mineral deposits behind, which can damage appliances over time. Also, it can conduct electricity, making it appropriate for certain scientific and engineering applications.
Deionized Water: Stripping Away Ions for Peak Purity
Deionized water goes a step further than distillation, removing virtually all the ions from the water. This process creates water that has extremely low electrical conductivity.
How deionization works
Water deionization involves running water through ion-exchange resins, which are materials that attract and bind to dissolved mineral ions.
What deionized water is used for
Because of its extreme purity, deionized water is often used in scientific and pharmaceutical applications. This ultra-pure water is essential for accurate experiments and consistent results.
You’ll also find deionized water used in a variety of manufacturing processes, as well as in automotive coolant and in biochemistry. In these applications, the lack of ions helps to prevent interference with the manufacturing process and helps to ensure accurate test results in the lab.
Distilled vs. Deionized: What’s the difference?
The main difference between distilled and deionized water is the way they’re purified. Distillation involves boiling water and then collecting the condensed steam. Deionization, on the other hand, uses ion exchange resins to remove ions.
Generally, deionized water is considered purer than distilled water. Distillation may leave behind some volatile organic compounds, while deionization is more effective at removing mineral ions. Because of this, deionized water typically has lower electrical conductivity than distilled water.
Applications Across Industries
Both deionized (DI) water and distilled water play important roles in a wide range of industries and even in your own home.
Scientific and Pharmaceutical Applications
Deionized water is essential for conducting precise experiments and getting consistent results in laboratories. It’s also the foundation for creating “water for injection” in the pharmaceutical industry, which must be free of contaminants.
Industrial Applications
In manufacturing, DI water is often used in machinery and temperature control processes, as well as in nanotechnology and the production of advanced electronics.
Distilled water is often used as a coolant in the automotive industry.
Other Applications
You may use distilled water in your humidifier or CPAP machine to avoid mineral buildup.
Frequently Asked Questions
Can I use DI water instead of distilled water?
In many applications, yes, you can. Both DI water and distilled water are highly purified. However, it’s crucial to consider the specific application. For some sensitive lab experiments or certain medical devices, distilled water might be preferred due to its removal of organic contaminants that DI water might not eliminate.
Is deionized water ok for a CPAP machine?
Using deionized water in a CPAP machine is generally discouraged. CPAP machines require water with very low mineral content to prevent mineral buildup and potential damage to the humidifier. Distilled water is the recommended choice because the distillation process removes minerals, organic compounds, and bacteria, whereas DI may not remove all organic compounds.
Why can’t you drink deionized water?
While drinking deionized water in small amounts is not acutely dangerous, it’s not recommended for regular consumption. DI water lacks beneficial minerals and electrolytes that our bodies need. Drinking it can disrupt the body’s electrolyte balance and potentially lead to health issues. Plus, it can taste rather flat and unpalatable, as the minerals that give water its flavor have been removed.
Is distilled the same as DI?
No, distilled water and deionized (DI) water are not the same, although both are purified forms of water. Distilled water is purified through a process of boiling water and condensing the steam, removing minerals, inorganic contaminants, and some organic contaminants. DI water, on the other hand, is purified through ion exchange, removing dissolved ions, though it may not remove certain organic contaminants or pathogens.
To Conclude
Distilled water and deionized water go through different purification processes. This results in different levels of purity, which makes each type of water better suited for specific uses.
Before you choose distilled or deionized water, think about why you need it. Do you need water that’s free of minerals? Does the water’s electrical conductivity matter? Are there contaminants that are especially important to avoid?
Choosing the right type of purified water will help your equipment work better and last longer. It will also give you more accurate scientific results and keep you safe.