Is Reverse Osmosis Water Good for Humidifiers?

We’ve all felt the pain of having dry skin, nose, lips, and even our eyes during the harsh winter weather or dry weather, which is precisely why we have purchased a humidifier for our homes to prevent all of this, but the question arises that whether using distilled water is better or reverse osmosis water is better?

The answer is distilled water. Always distilled water. Why? It’s because reverse osmosis still has some minerals added into it, and while those minerals are good for human health, they end up causing more damage to your humidifier as opposed to distilled water.

Why Should You Not Use Reverse Osmosis Water in a Humidifier?

Let’s talk about what reverse osmosis water is. Reverse osmosis water is generally a type of water that has been filtered through many times in order to remove unwanted minerals and impurities so that humans can consume the water.

Once the water has been passed through many filters, good minerals are added back to the water that is essential for human health.

Is Reverse Osmosis Water Good for Humidifiers?

However, the issue is that while reverse osmosis is an excellent alternative to distilled water, it is still not impurity free.

Using this water in a humidifier will cause problems because eventually, the minerals will become hard residues that settle into the filters of the humidifier, causing more severe damage and forcing you to buy a new humidifier.

We often forget that the purpose of a humidifier is to release tiny water vapors into the environment to combat dryness.

Still, suppose the water contains any form of bacteria (regardless of whether the bacteria is good for humans’ internal system). In that case, it will fester in the environment, causing more mold and other harmful bacteria to build up.

The rule to remember is that a humidifier will spread water onto everything and into everything; hence while the reverse osmosis water might not affect our human bodies, it can cause issues in your home.

An example would be the patch of mold in the corner of your home. This was a result of using bacteria-filled water, which settled onto the corner of the wall and ended up becoming a far worse bacterium.

You are now consuming that harmful bacterium by breathing it in. Hence, Reverse osmosis water vapors might not directly impact you, but they will impact you indirectly.


Distilled Water is Better And Here’s Why!

Unlike reverse osmosis water, distilled water does not contain any impurities. It has no bacteria in it, which is why this form of water is an optimum choice to be used in a humidifier.

As I mentioned, a humidifier creates water vapors that are released into the environment and settle onto everything, including your walls, table surfaces, clothes, skin, and all other possible things you can see.

Since distilled water does not contain any form of bacteria, you will not have to worry about any bacterium plaguing the corner of your walls or clothes.

Remember how we used to learn in science class that fungus or mold grows best in a moist environment? The same concept applies here. When bacteria are mixed in water and then it is released as water vapors, they will only grow and fester greatly.

This is why using water that contains ZERO bacteria in it will be a better choice because it won’t settle onto walls and grow into mold or fungus.

Additionally, since distilled water has no minerals or bacteria in it, there is almost no chance of water salts depositing into the filters of the humidifiers, which means that you won’t have to send your humidifier for maintenance as often.

Does Reverse Osmosis Water Induce an Allergic Reaction?

YES. A big yes. Always remember that a humidifier spreads water vapors into the environment, so any bacteria it contains will also spread along with it. Since reverse osmosis water has impurities and bacteria, it will release into the atmosphere, making it settle into surfaces that are not often being cleaned, like walls.

Is Reverse Osmosis Water Good for Humidifiers?

Now since bacteria is being spread through the medium of water, it will cause bacterium like fungus and molds to grow in different locations that are not being accessed regularly, like those coats in your closet that are not being used or those shelves that are not being cleaned. That mold or fungus will end up triggering health issues, and if you’re highly prone to allergic reactions, reverse osmosis water will definitely activate it.

Remember, though, that reverse osmosis water doesn’t “directly” trigger your allergies. It sends bacteria into the environment, which grow into worse colonies of bacteria, and then those bacteria are what end up starting your allergies.

We advise all those people with allergies and all those people who have newborn babies living in their homes to use distilled water in the humidifiers because it is bacteria free and will not cause any health issues in the future.

Reverse osmosis water doesn’t just cause allergic reactions, but because of high minerals in it, it will cause mineral deposits to be left behind onto metals or humidifier filters which can erode them, and you will end up spending a tremendous amount on fixing it. Think of long-term drawbacks and try to stay clear from reverse osmosis water.

In What Scenario Should We Use Reverse Osmosis?

A short answer would be that reverse osmosis water can be used for drinking purposes, but it should never be used in a humidifier. Since reverse osmosis water is filtered water, it contains impurities and bacteria that are good for human consumption.

Still, if it is used in humidifiers, those bacteria will spread all across your house, and if you’re someone with a germ phobia like me, then it’s best to avoid reverse osmosis water used in your humidifiers.

Remember that reverse osmosis water can be consumed through drinking because it is acidic in nature. Tap water is alkaline, but reverse osmosis water is acidic because calcite is added to it, which brings the pH level of the water to less than 7 and increases the number of hydroxonium ions in it.

This makes the reverse osmosis water acidic, but it is actually quite beneficial if you drink the water as opposed to using it in your humidifiers because of the minerals that are present in it.

Distilled water does not have any minerals in it, which is why it is considered as “pure water” and not ideal for drinking but still better for humidifiers.

Benefits of Using Distilled Water

As mentioned, distilled water is an ideal choice to go for when using water in humidifiers. It does not have any bacteria or minerals in it that would harm the environment or even the humidifier itself.

Here are a few reasons why using distilled water is better:

Improved air quality:

Using distilled water aids in improving the air quality in your home. The reason is simple. There are no impurities or bacteria that are being spread into the environment.

Essentially, a humidifier takes the water and converts it into tiny water vapors so that your home environment is not dry; so by using distilled water, you will not see those dust-like particles sitting around, and you can breathe through pure water vapors.

Prevention of fungus or mold

Bacteria in reverse osmosis water can cause fungus in the corner of the walls or behind your curtains, but with distilled water, no bacteria will be released into the environment, and no mold or fungus will be developed.

Clean humidifier

Using distilled water ensures that your humidifier remains clean. Since distilled water does not even contain minerals, you will not see deposits settling into the filters or scale build-up, which means you won’t have to clean it as often as you would have using reverse osmosis water.

How to Clean or Descale a Humidifier?

When you use reverse osmosis water (mineral water) or tap water even, it contains high amounts of minerals like calcium or magnesium that cause a reaction and leave white scales on the base and walls of the tank that’s situated inside the humidifier.

This is the biggest reason for using distilled water is that it doesn’t build up any white scales and doesn’t leave behind any residue build-up either. With the use of distilled water in your humidifiers, you won’t have to clean them as often.

However, if you’ve been using reverse osmosis water for quite some time and you’ve noticed scale build-up, but now you want to clean it instead of replacing the tank, then we’ve made it easy for you by following the outlined steps:

  • Unplug the humidifier and remove the tank
  • Empty the tank so that you can go ahead to clean it.
  • Use food-grade hydrogen peroxide solution to clean the scale deposits at the bottom and side of the tank.
  • Use a dry cloth with the solution poured onto it and then gently start pressing onto the white residues to remove it
  • If the scale build-up is thick and hard to remove, then fill the entire tank with hydrogen peroxide so that the build-up becomes diluted and removed automatically.
  • Leave the solution on for 30 to 40 minutes and then drain the solution (make sure that the tank is not inside the humidifier and the humidifier is not turned on while this process is taking place)
  • Drain the liquid and if you still see some patches of scale in the crevices, then use a small brush to clean it.
  • Once this is done, use a bleach solution to disinfect the tank
  • After this, clean the tank with water under the sink so that it is thoroughly cleaned and ready to be used again
  • Make sure the tank is dry before placing it back into the humidifier

If your humidifier varies according to its tank size and removal procedure, then either check the manual to see how to remove the tank or contact the company to understand the procedure.

Humidifiers also Deserve Care and Effort

Don’t let your humidifier tank reach a point where you see a thick wall of build-up. It’s better always to keep taking preventative measures so you don’t have to waste a buck on maintenance. We recommend doing the following tricks to keep your humidifier clean and safe:

  • Use hydrogen peroxide every third day, even if you do not see any signs of build-up. This method will prevent any future scale build-up.
  • Use only distilled or pure water so that there are no bacteria spreading in your homes.
  • Refill the water tank of the humidifier every day.
  • Make sure to clean and dry the tank before adding in fresh water.
  • Do not leave water inside the tank for days on end because that just paves the way for more bacteria to grow on the surface and cause more health issues.
  • If the weather is not as dry and you do not need to use the humidifier, then disassemble it and place it in a dry and clean place for later use.

In What Conditions to Use a Humidifier?

You should definitely consider investing in a humidifier in harsh winter weather or dry weather. If you belong from a region where such conditions are quite prevalent, then a humidifier will be your best friend, but if you belong to a humid region, then a humidifier might cause more respiratory issues rather than aid in good health.

If you witness symptoms like dry cough, dry or itchy eyes, sore throat, and highly dried out skin even though you’re drinking tons of water, then invest in a humidifier right away.

According to the EPA, an ideal environment with humidity levels should be around 30 to 50 percent, which is why we recommend buying a hygrometer to check the hydration levels constantly. If the levels are below this set amount, turn on your humidifiers and use only distilled water.

All in all, the apparent choice of water to go for while using humidifiers is distilled water because it is not only bacteria-free, but it is mineral-free as well, which means that you will not have to clean the scale build-up regularly, and you won’t have to worry about more bacteria or germs spreading in your home.



This is my blog about the ways and solutions that can help you improve your health by taking more value from drinking water. As improving health means a lot to me, I decided to create the Water On Top project with the purpose to reveal the benefits of water, the finest products to take our daily water to another level, and much more great stuff about water that I believe is on top of our nutrition.

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