Is Distilled Water Hard Or Soft? (a Water Doctor Explains)

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If you’ve been looking at buying a water distiller or you regularly buy distilled bottled drinking water, you might be wondering whether distilled water is hard or soft.

In this guide, we’ve answered this question, as well as other questions you might have about water produced by distillation.

📌 Key Takeaways:

  • The main difference between distilled and soft water is that distilled water is free from all impurities (including hard water minerals), while soft water may still contain impurities but doesn’t contain hardness minerals.
  • Use a water distiller if you want to drink distilled water that’s guaranteed to be pure, safe, and contaminant-free.
  • Use a water softener if you want to protect your home’s plumbing and appliances from calcium and magnesium, which form insoluble deposits called limescale.

⚖️ Soft Vs Hard Water

Before we look at the soft or hard properties of distilled water, we need to understand the differences between soft and hard water. This will also help us to explain the distillation process and how it alters water’s hardness.

Simply put, soft water is water that has a low concentration of dissolved minerals.

The dissolved minerals that contribute to hardness include calcium, magnesium, chlorides, and sulfates.

Hard water, on the other hand, has a high concentration of these minerals.

Due to its high mineral content, hard water has slightly different properties from soft water. It’s more alkaline and has a stronger mineral taste. Hard water also produces limescale deposits, which is why so many people want to find a good solution to soften their water at home.

Hard water vs soft water on plumbing fixtures

🤔 Is Distilled Water Soft?

Yes, distilled water is classed as soft water because it has a low mineral content.

The water distillation process involves boiling water until it evaporates, then directing the water into a clean container, where it cools and condenses. This separates the water molecules from the other molecules and particles present in the original source.

The contaminants and impurities with higher boiling points than water, including water hardness minerals, are left behind in the boiling chamber.

That means the purified water that’s produced has a very low concentration of minerals and dissolved salts, so it’s known as soft water.

A water distiller should produce soft water regardless of the water’s initial calcium and magnesium or dissolved solids content.

You should notice that water from a distiller has a “flat” taste due to its lack of minerals and impurities.

Because of its inability to form mineral buildup, soft water from a distiller is a good water source to use in car cooling systems, steam irons, aquariums, and any other equipment that requires impurity-free water that won’t leave scale deposits.

Illustration of the distillation process

Continue Reading: The Truth About Distilled Water: Is It Safe to Drink?

🆚 Softened Water vs Distilled Water

So, now you know that distilled water is technically soft water – what’s the difference between distilled and soft water from a water softener?

Distilled water is purified water that’s produced in a water distiller, while soft water (or softened water) is water with a low mineral content that’s produced in a water softener.

Unlike pure distilled water, soft water is not impurity-free. The only purpose of water softeners is to soften water by exchanging magnesium and calcium ions with sodium ions.

That means softened water is free from all the minerals that contribute to water hardness, but it’ll still contain the other impurities found in the water supply, such as disinfectant chemicals and heavy metals.

The purpose of water softeners is different from that of water distillers.

A water softener’s aim is to eliminate the aesthetic effects of hard water, like clogging of pipes, limescale on shower screens, faucets, and fixtures, and soap scum.

A water distiller’s aim is to produce purified, demineralized water that contains only H20, with nothing extra, primarily for drinking and other POU applications.

Pouring distilled water from glass container

⚗️ Should You Use A Water Distiller To Soften Your Water?

Since water distillers can soften water, should you use a distiller primarily for this purpose?

There are a couple of reasons why we DON’T recommend using a water distiller to soften your water:

Won’t Protect Your Whole Home

Soft water has no particular health benefits. In fact, it’s considered slightly less healthy than hard water because it contains only very low levels of calcium and magnesium minerals, or no minerals at all, which are needed in the human body.

The main reason why most people choose to soften their water is for the aesthetic benefits in their plumbing system and appliances.

Hard water leaves mineral residue and limescale deposits that clog pipes, contribute to corrosion, slow water flow, and reduce appliance efficiency.

Water softeners are installed at the main water line in your home, meaning they can protect against all the effects of hard water in your entire home’s plumbing system, fixtures, and appliances.

Water distillers, on the other hand, are countertop units that are designed to distill drinking water at the point of use.

There’s no such thing as a point-of-entry water distiller. So, you couldn’t use this system to soften your whole home water supply, and there’d be no point in using this system simply to achieve soft drinking water, since there are no specific health benefits of soft water alone.

Extra Cleaning & Distiller Maintenance

Another reason why we don’t recommend a water distiller for treating hard water is that you’ll have to work harder to clean the accumulated minerals from the boiling chamber.

Calcium and magnesium minerals form limescale on all surfaces that they come into contact with, including the inside of the water distiller’s boiling tank.

The harder your water (i.e. the higher the calcium carbonate concentration), the more limescale deposits the water will leave in the distiller.

So, if you plan to use a water distiller to tackle very hard water, your cleaning duties between producing batches of distilled water will be greater.

You could save all the hassle of cleaning a water distiller’s boiling chamber by simply installing a water softener at your main water line, which cleans out the resin bed automatically.

Limescale formation inside water distiller

📋 So, What Are Water Distillers Used For?

You might be wondering about the purpose of a water distiller if it isn’t worth using to produce soft water.

The main reason why people use water distillers is to produce pure, clean drinking water that’s free from trace contaminants and has none of the potential health effects of normal tap water.

For many people, the fact that distillers produce soft water is simply an added feature of little importance.

Distillation removes virtually all dissolved impurities in water. This purification process removes heavy metals, chemicals, microorganisms, and all the minerals present in a tap water supply, which guarantees safe water for drinking.

Filling the imber isla water distiller

📑 Final Word

Soft and distilled water both have their uses and benefits, but don’t confuse them as the same thing.

What’s the best water treatment solution for you: distillation or water softening?

👨‍🔧 If your main priority is to achieve purified water for drinking, a water distiller is the best solution for you.

👨‍🔧 But if pure water production isn’t your priority and you’re much more interested in the benefits of soft water, the best way to get your whole-home supply of water softened is by installing a water softener.


Can soft water be used in a CPAP?

No, we don’t recommend using soft water in a CPAP because this type of water could still contain chemicals and bacteria that could lead to buildup in your CPAP machine. Most doctors and scientists recommend distilled water for a CPAP, because this water is soft and free from all impurities so won’t damage your CPAP machine and is healthy to breathe in.

What is the water hardness of distilled water?

The water hardness of distilled water should be close to 0 because distilled water is classed as soft water. That’s because the distillation process removes all the minerals that contribute to water hardness.

Is distilled water artificially softened?

Yes, distilled water is technically artificially softened because the process involves removing minerals that are naturally present in the water. On the other hand, naturally softened water is water derived from a naturally soft water source. However, nothing is added to the water to soften it, and distillation is a natural process that occurs in the environment, so the process itself doesn’t involve the use of artificial techniques.

Is soft water the same as distilled water?

No, soft water isn’t the same as distilled water. Soft water has a low hardness mineral content, but it’s still likely to contain other impurities that don’t contribute to hardness. Distilled water is soft, and it’s also impurity-free, because the distillation process removes all dissolved salts, solids, minerals, chemicals, and metals.

  • Jennifer Byrd
    Water Treatment Specialist

    For 20+ years, Jennifer has championed clean water. From navigating operations to leading sales, she's tackled diverse industry challenges. Now, at Redbird Water, she crafts personalized solutions for homes, businesses, and factories. A past Chamber President and industry advocate, Jennifer leverages her expertise in cutting-edge filtration and custom design to transform water concerns into crystal-clear solutions.

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