How to Deionize Water: A Complete Guide

Welcome to our comprehensive guide on how to deionize water. In this article, we will provide you with a step-by-step process to deionize water and explain the benefits and drawbacks of this method. We also include a table with all the information you need to deionize water successfully.

What is Deionized Water?

Deionized water (DI water) is water that has had its mineral ions removed, producing water that is almost entirely pure. Deionization involves the removal of cations (positively charged ions) and anions (negatively charged ions) through a process called ion exchange.

Deionized water is commonly used in scientific research, the pharmaceutical industry, and manufacturing processes that require high-purity water.

How is Deionized Water Different from Distilled Water?

Although both deionized water and distilled water are pure and free of minerals, they are different. Distilled water is produced by boiling water and then collecting the steam, which is condensed back into liquid form. This process removes most of the impurities, including minerals, from the water.

Deionization, on the other hand, removes impurities by ion exchange. Deionized water is often used when distilled water is not pure enough for a specific application.

How to Deionize Water

Step 1: Choose a Deionization Method

There are two main methods for deionizing water: ion exchange resin and electrodeionization.

Method Pros Cons
Ion Exchange Resin – Lower cost
– Simple to operate
– Requires frequent resin regeneration
– Can add impurities to water during regeneration
Electrodeionization – Does not require chemical regeneration
– Produces high-purity water
– Higher cost
– Requires electricity

Step 2: Set Up Your Equipment

Follow the instructions for your chosen deionization method to set up your equipment. Generally, this will involve connecting a water source to the equipment and ensuring the proper resin is in place.

Step 3: Run the Water Through the Equipment

Turn on the equipment and allow the water to run through it. Follow the manufacturer’s instructions for the recommended flow rate and time.

Step 4: Test the Quality of the Deionized Water

Test the water to ensure it has been successfully deionized. Most methods come with a tester that measures the total dissolved solids (TDS) in the water. The TDS should be close to zero for deionized water.

Step 5: Store the Deionized Water

Store the deionized water in a clean, dry container that is free of contaminants.

Advantages and Disadvantages of Deionizing Water


– Produces high-purity water that is free of minerals
– Can be used in a variety of applications that require pure water


– Can be expensive to set up and maintain, depending on the method chosen
– Deionizing water can be time-consuming

Frequently Asked Questions

Q: Can I drink deionized water?

A: It is not recommended to drink deionized water as it lacks essential minerals.

Q: How often should I regenerate the ion exchange resin?

A: This will depend on the quality of your water and the capacity of your resin. Generally, you will need to regenerate the resin when the TDS of the water exceeds the recommended level.

Q: Can I use deionized water for cooking?

A: Yes, deionized water can be used for cooking.

Q: How long does it take to deionize water?

A: The time required for deionization will depend on the flow rate, resin capacity, and method used. Generally, it takes a few minutes to an hour.

Q: Can I use tap water for deionization?

A: It is recommended to use distilled or reverse osmosis water for deionization, as tap water can contain impurities that can interfere with the process.

Q: How long does deionized water last?

A: Deionized water can last for several months if stored properly in a clean, dry container.

Q: Can I reuse the ion exchange resin?

A: Yes, it is possible to regenerate and reuse the ion exchange resin.

Q: Is deionized water safe for aquariums?

A: Deionized water can be used for aquariums, but it must be properly remineralized before use.

Q: Can I use deionized water for my steam iron?

A: It is not recommended to use deionized water in steam irons as it can cause damage to the iron.

Q: Can I use deionized water in my car battery?

A: It is not recommended to use deionized water in car batteries as it lacks the minerals required to conduct electricity.

Q: What is the difference between deionized water and ultrapure water?

A: Ultrapure water is water that has been treated to an even higher degree of purity than deionized water, typically through a process called reverse osmosis.

Q: Can I use deionized water to wash my car?

A: It is not recommended to use deionized water to wash your car as it lacks the minerals that help to protect the car’s paint.

Q: Can deionized water conduct electricity?

A: No, deionized water cannot conduct electricity as it lacks mineral ions.

Q: Can deionized water corrode metal?

A: Deionized water is not corrosive, but it can still cause damage to certain metals if they are not properly protected.

Q: Can I use deionized water for my humidifier?

A: Yes, deionized water can be used in humidifiers.


Deionized water is a valuable resource for industries that require high-purity water. By following the steps outlined in this guide, you can deionize water and ensure it is free of minerals and impurities. Remember to choose the right method for your needs and take proper care of your equipment.

We hope this guide has been informative and helpful. If you have any further questions or comments, please feel free to reach out to us.

Take Action Today

Ready to deionize water for your needs? Invest in the proper equipment and follow the steps outlined in this guide to ensure you have pure, high-quality water for all your applications.


The information provided in this guide is for educational purposes only. We are not responsible for any damage or injury that may result from following the steps outlined in this guide. Always use caution and follow the manufacturer’s instructions when working with equipment.

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