Best Hard Water Humidifier Reviews: Revealing Best Units

Sample this: You live in a place with dry air, so you need a humidifier to increase humidity. However, you find out that you have hard water. This is why you need the best hard water humidifier.

But is there such a thing as the best humidifier for hard water? That is what we are going to find out in this post.

In another article, we looked at tablets for humidifiers. We saw how they work and how they can make it possible to use hard water in a humidifier without causing it any harm.

Really, are there humidifiers for hard water?

Any humidifier can work with hard water. After all, water is just that—water. However, the problem here is that ultrasonic humidifiers leave white dust.

Thus, when we ask whether there are humidifiers that can work with hard water, what we are asking is whether they will add moisture to your indoor air without leaving white dust.

And yes, there are several. Cool mist humidifiers work very well. However, please note that you will have to clean yours more often. The minerals create scale on the wall.

Hard water also affects the humidifier filters. You have to clean or replace them more often than when using soft water.

You can also use hard water in a warm mist humidifier. When the water boils, the minerals form a layer at the top. Thus, the mist coming out of the unit does not leave white dust.

However, the downside of using hard water in a warm mist humidifier is the coat of minerals the water forms on the heating elements.

Humidifiers that you can use for hard water have one of the following two things:

  • It can have a demineralization cartridge
  • It can have a water filter

The best hard water humidifier to buy

There are so many humidifiers on the market. If this is your first time buying one to use with hard water, you might find it a bit hard to choose the top-rated one. Here, we have done the footwork for you, and we bring you three incredible units that you can use if your water has minerals.

HoMedics TotalComfort Warm and Cool Mist Ultrasonic Humidifier

 You can buy the HoMedics TotalComfort Warm/Cool Mist Ultrasonic humidifier on It comes with a demineralization cartridge, which removes the minerals from the water.

Design and build quality

Even before we can delve into the features of this unit, we are amazed at how good it looks. It is incredibly good! The black and blue colors make it stand out.

This is a dual-tank humidifier by design. It comes with two water tanks. Both of them have a capacity of 1.7 gallons. To keep the humidity level in your house at 30 to 55%, this unit can run for up to 80 hours.

Image of hard water humidifier

For durability, each of the tanks has a double plastic casing. Should you drop the unit accidentally, the tanks will not burst open. However, know where best to position the humidifier to prevent such freak accidents.

Demineralization cartridge

Please note that this unit does not come with built-in demineralization cartridges. Rather, these are offered as a bonus—two of them. You can fix them inside the unit so that they can remove the minerals from the water.

Since this is an ultrasonic humidifier, if you do not remove the minerals, the mist will leave a trail of white dust on your surfaces.

Auto shut-off function

If the humidifier runs low on water, it will shut off automatically. In another article, we asked what can happen if you run a humidifier without water.

You do not want to find out about this one. For safety, it will shut down when the water runs low in the tank.

Mist control settings

If you live in a very dry area and you need fast mist output, there is a setting for that on this mister. At fast mist output, the two tanks might not run for the said 80 hours.

At a low mist setting, this mister will run for up to three days non-stop.


This is a kind of self-cleaning technology that prevents mold in humidifier symptoms. It is also antimicrobial, so bacteria cannot thrive inside the tank. Remember, any mister unit disperses whatever is inside with the mist.

Check the price of HoMedics TotalComfort unit on

Please note: while we have reviewed the ultrasonic mister from HoMedics, there is a warm mist one.

MegaWise Healthy Top-Refill Cool Mist Humidifiers

Your search for a mister that can soften hard water stops with the MegaWise Healthy Top-Refill Cool Mist Humidifiers that you can buy on

Image of best room humidifier for hard water

This unit is like a three-in-one unit of sorts, and I will show you why. Keep reading!

Design and build quality

By design, this is a top-fill mister, so there is no trouble at all when you are adding water to the tank. The tank is made of clear plastic, so you can see the level of the water. Also, this unit comes in three models. There is one with 1 filter, while the other models come with 2 and 3 filters.

This misting unit has a capacity of 1 gallon or 3.5 liters. This can run for up to 35 hours.

Essential Oil Diffuser

This humidifier comes integrated with an essential oil diffuser. Instead of adding essential oil in a humidifier for babies, just get this one. It is going to dissipate a nice fragrance depending on the essential oils that you use.

Essential oils in cool mist units can help to de-congest your baby. However, you should read the age recommendation on the oil packaging before using it on your baby. It is better to err on the side of caution.


Even if you buy the one with the single filter, it is going to do an excellent job of filtering the minerals, bacteria, and mold out of the water.

Your child’s safety and health is assured, even if you keep this unit running for a long time. However, remember that 60 to 70 percent humidity can cause mold.

The filter is contained in a cartridge, and it is detachable if you have soft water. When running the mister on hard water, one filter cartridge can be used for up to 40 tanks of water. This is quite a good deal.

Low noise level

This is a perfect unit to use in a baby’s room, thanks to the low noise levels. At a high-speed mist setting, it makes a 30 dB noise. At low settings, it makes a 26 dB noise level. Your baby can happily sleep through this, considering that you will not keep it too close to their cot.

Finally, this humidifier has an array of seven display light colors. All of these are soft lights, so they will not disrupt your baby’s or your sleep.

Pure Guardian H1510 Ultrasonic Cool Humidifier for Hard Water

Image of best PureGuardian mister

From what we have seen in past Pure Guardian reviews, this is a good brand name. It lasts a long time and does its job of increasing humidity safely.

So what makes this unit good for use in a place with hard water? The secret is in the features. So keep reading!

You can check the price of this humidifier on

Design and build quality

First, you can buy a cool mist or warm mist ultrasonic version of this unit. This is a filterless humidifier so it is not going to filter out minerals in your hard water.

How does it help with hard water? Well, to be truthful, this is not going to help with hard water. Thus, you will have to clean it often to remove the scale that builds on the walls of the tank.


This unit comes with the SILVER CLEAN technology that is exclusive to Pure Guardian (well, other brands have the special cleaning technologies that they call other names).

What this technology does is prevent the formation of slime on the walls of the tank. In effect, this prevents the formation of mold. Thus, you cannot experience humidifier sickness symptoms.

Easy-fill Tank

By design, this is a simple-looking humidifier for hard water because it is simple! For instance, while others are high, this one is short. It is hard to tip over.

The tank design is top-fill. The benefit of this is that it is easy to fill with water and it is easier to clean. The tank size is 1.5 gallons. It has a space rating of 630 square feet. On a low mist output setting, the unit can run for close to 100 hours.

If you need aromatherapy …

If you need some aromatherapy, you can look for the H1510 model with an essential oils tray. Just a few drops of your menthol, lavender, or rosemary essential oil can enhance your comfort a great deal. Similar to the Vicks humidifiers that come with scent pads, this one can also help with coughing and congestion.

Myst Ultrasonic Humidifier Mist Vaporizer with Water Filter

You can order the Myst Ultrasonic humidifier for hard water on

This smart humidifier can help with hard water. When the humidity in the room reaches the set level, it stops pumping mist into the room. If the humidity level dips below the set level, it starts to release mist again.

Image of humidifier with filter for mineral water

But first, the features!

Design and build quality

There are so many good things to say about the Miko Myst ultrasonic humidifier for hard water. First, the tank is easily detachable from the base. Cleaning it is so easy. You don’t need to unplug the unit from power when you want to add water or clean the tank. While the tank is not opaque, a small transparent strip will show you how much water is remaining.

Tank size

Albeit being the best humidifier for hard water, it has a small tank that is 1.2 gallons in capacity. At low-speed mist output, it can run for about 40 hours, which is quite good. On the same note, the space rating for this unit is 540 square feet, so it is going to be enough for your bedroom or living room.

No leak design

This is one of the best things about this small unit. The anti-leak design is patented, so it is really hi-tech. The tank is secured to the base using magnetism, and the unit will not start to pump mist unless the tank is 100 percent secured to the base.

Remote control

This is another great feature of this humidifier. You can use the small remote controller it comes with to turn the humidifier on, off, or enter some other setting without having to go to the unit. This saves you the hustle of waking up at night just so you can go punch some buttons on the unit.

It has sleep mode

When you want to turn all the lights off and still leave the unit running in the bedroom, just engage in sleep mode. Because the noise level is really low, even your baby can sleep through it. If you like, you can program the unit to control your breathing patterns in a process called guided meditation. You can program the lights to match your breathing pattern.

Essential oil pad

For aromatherapy, you can use essential oil pads/scent pads in the pad at the back of the unit. Aromatherapy can help you to relax, and enjoy your sleep, and some flavors, such as menthol, can help decongest you.

Check the price and other features of the Myst Ultrasonic humidifier on

Best humidifier for hard water FAQ

At times, reading a review for the best humidifiers for hard water is not enough. If you still need some clarification this far, this section on the frequently asked questions might help you.

Can you use hard water in an ultrasonic humidifier?

An ultrasonic humidifier such as HoMedics TotalComfort Cool mist unit comes with a demineralization cartridge, which means you can use it with hard water. The cartridge removes all the minerals from the water, in effect softening it. Just don’t use an ultrasonic mister that does not have a filter or demineralization cartridge.

What kind of humidifier doesn’t leave a white residue?

Warm mist humidifiers do not leave pale dust because they do not dispel minerals with the mist. The mineral layer sticks to the tank walls. Evaporative humidifiers also do not leave white dust. Only ultrasonic humidifiers without filters leave mineral dust.

Can hard water ruin a humidifier?

If you do not remove minerals from your water using a demineralization cartridge or filters, it can clog your humidifier and damage it. If you start seeing white dust deposits on your surfaces after running a humidifier, check it and clean it more often.

What is the hard stuff in my humidifier?

This is mineral scale that comes from hard minerals in your water. The scale sticks to the tank walls when the water evaporates as mist.


Choosing the best hard water humidifier is not too hard. Just ensure that it comes with features such as a filter, demineralization cartridge, timer, auto shut-off, and other functions.

If you have been wondering whether you can use hard water in a humidifier, the answer is yes, you can. The ones that we have reviewed here are designed to work with hard water.

The only problem is that the one without a filter or demineralization cartridge will not prevent the formation of white dust in your house.

When you get your mister, be sure to maintain a good cleaning regime. Humidifier hard water deposits stay on the walls of the tank as scale. If you have a warm mist-hard water humidifier, the mineral scale can coat the heating elements.