glass of water

Is Deionized Water Safe To Drink?

Pure water, in its most fundamental sense, is H2O that’s free from impurities, contaminants and additives. It is water in its simplest and most unadulterated form. It’s achieved through processes like distillation or deionization, and is essential to various industrial, laboratory, and medical applications where impurities could interfere with processes or experiments. 

Now, pure water may sound like the best way for you and your family to hydrate. But you and your family don’t live in a lab. Yes, you want clean, safe, great-tasting water. No, you don’t need water so pure that it’s devoid of naturally occurring, health-giving minerals or capable of leaching minerals from your body.  

Here, we explore whether deionized water is safe to drink. We’ll also compare this specialized purification process with four-stage reverse osmosis, a tried-and-tested water filtration system process that not only cleans your water but, with the addition of the right filter, can enhance it too.


What is deionized water?

In its natural state, water contains various minerals, salts, and other charged particles, known as ions, which contribute to its conductivity and may affect its suitability for certain applications. Deionized water, often known as DI water, has undergone a process to remove ions. However, it doesn’t remove impurities that don’t have a charge, like pathogens or organic pollutants (unlike reverse osmosis). 

The deionization process involves passing water through special ion exchange resins that attract and bind to these ions, effectively removing them from the water. The result is water with a significantly reduced ion concentration, often approaching or reaching zero. The most common ions targeted are cations (positively charged) and anions (negatively charged).


process of water deionization


In some systems, mixed bed deionization is used. This involves combining both cation and anion exchange resins in a single unit. This ensures a high level of purity, often achieving near-complete removal of ions.

Deionized water is sometimes also referred to as demineralized water or distilled water, but these terms can have slightly different meanings depending on the specific purification method used.


How is deionized water used?

Deionized water’s unique properties make it a valuable resource in settings where even a trace impurities could have significant consequences. Its purity is ideal for tasks such as: 

Laboratory and scientific research

Deionized water is a staple in laboratories and scientific research settings where precise and uncontaminated water is crucial for experiments, tests, and analytical procedures.

Electronics manufacturing

Industries involved in electronics manufacturing, such as semiconductor and microchip production, use deionized water to prevent contamination that could affect the performance of electronic components.

Medical equipment

Deionized water is commonly used for cleaning and maintaining medical equipment, ensuring that no impurities compromise the functionality or safety of the devices.

Automotive industry

In automotive applications, deionized water is used in processes like battery manufacturing and cooling systems to prevent mineral deposits and extend the life of equipment.

Cosmetic and pharmaceutical production

The purity of deionized water makes it suitable for use in the production of cosmetics, pharmaceuticals, and other sensitive products where water quality is critical.


Can you drink deionized water?

glass filling up with tap water from a faucet in a sink


Now, here’s where it gets interesting. The big question: is deionized water safe to drink? The short answer is yes – but hold your horses. 

It shouldn’t be your main source of hydration. 

Keep in mind that, while deionized water is excellent for certain uses, it is not typically recommended for regular consumption because it lacks the necessary minerals for a balanced diet. Here are five reasons why deionized water isn’t great to drink:

1 Lacks essential minerals

Deionized water doesn’t have calcium, magnesium, and potassium. These minerals play a vital role in maintaining the body's electrolyte balance and supporting various physiological functions. Drinking water that lacks these minerals may not contribute to your overall mineral intake.

2 Aggressive absorption of minerals

Deionized water is often described as “hungry” water because it tends to absorb minerals and ions from its surrounding environment. When consumed, it may leach minerals from the body, including the gastrointestinal tract, potentially leading to mineral imbalances.

3 Electrolyte imbalance

Continuous consumption of deionized water may contribute to an electrolyte imbalance in the body. Electrolytes are essential for proper nerve function, muscle contraction, and fluid balance. The lack of these ions in deionized water may disrupt these physiological processes.

4 Container material leaching

Because deionized water is highly pure and lacks ions, it has the potential to leach materials from the containers in which it is stored. This can introduce substances into your water that may not be suitable for consumption.

5 Unpleasant taste

Some people find the taste of deionized water to be flat or bland due to the absence of minerals. This lack of taste may make it less enjoyable for regular consumption.


Deionization vs reverse osmosis: what’s the difference? 

In a nutshell, reverse osmosis removes pathogens and organic contaminants like E. coli, Crytosporidium and pesticides. Deionization does not. 

Technically speaking, deionization shreds through ions, leaving you with highly purified water that’s perfect for essential practical applications. Reverse osmosis removes impurities by pushing water through a semipermeable membrane and, if your system has a remineralizing filter, runs healthy minerals back into the water. 

Here’s the kicker: you don’t need to deionize after reverse osmosis. Reverse osmosis is a water purification process that effectively removes a wide range of impurities, including ions and dissolved solids, from water. 

In the reverse osmosis system, water is forced through a semipermeable membrane, leaving behind contaminants and producing purified water on the other side. And because reverse osmosis is such a thorough and efficient method of water purification, additional deionization isn’t necessary. The process already significantly reduces the concentration of ions in water, achieving a high level of purity that’s ideal for keeping your family safe, healthy and hydrated. 


Benefits of reverse osmosis filtration

Peace of mind

With 0.0001-micron pores, a reverse osmosis membrane can remove a broad swath of dangerous contaminants, such as forever chemicals and lead. So when you install a reverse osmosis filtration cooler, you ensure fresh, clean water is easily accessible.


Because a reverse osmosis filtration system works with your home or office’s own water system and typically comes with a dedicated faucet, purified water is always available. It empowers everyone in your home or office to make healthier hydration choices

Tastes great

Water that’s had the chlorine removed from it tastes far more pleasant, so it goes without saying that foods cooked with or in reverse osmosis-filtered water will be more palatable, too. It’s ideal for preparing baby formula, tea, coffee and cocoa, as well as cooking hot cereals, soups, rice and pasta. 

Kind to the environment

With a reverse osmosis filtration system, there’s no need to sign up for an expensive bottle delivery service and no worries about water bottles running low. Plus, you can kick the single-use plastics habit to the curb for good.

Enhances your H2O

With the simple addition of a remineralizing filter, a four-stage reverse osmosis system can remineralize your purified water by adding healthy minerals, such as magnesium, calcium, potassium and selenium, back into the water, keeping you healthier and water tastier.. 

While deionized water is not suitable as a primary source of drinking water, it plays a crucial role in specific industrial and laboratory processes where ultra-pure water is required. For everyday hydration, we recommend consuming water from reliable sources that provide a balanced mineral content. Browse our four-stage reverse osmosis water filtration coolers and filter systems today.
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