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6 Best Humidifier For Hard Water 2023 – Purchased & Tested

While we always advocate for the use of distilled water in humidifiers, we can’t ignore the fact that tap water is the go-to choice for many due to its convenience and cost-effectiveness.

Even though approximately 85% of American households have hard water, manufacturers rarely mention whether their humidifiers are specifically designed for hard water use.

But fret not. We’ve got your back. We’ve conducted extensive testing on numerous models and have compiled a list of the best humidifiers for hard water. We’ll also answer all the burning questions you may have about using humidifiers in such conditions.

Honeywell cool mist humidifier  is a great option because it uses wicks to filter out the mineral substances and impurities in the water and is quite easy to use. Levoit 300s  can also work well with hard water even if it is an ultrasonic model. It has many advanced features.

So, without further ado, let’s dive right in and discover the perfect humidifier solution for your hard water needs!

Why you can trust this review: We purchased these humidifiers with our own money, took pictures, and spent at least two weeks testing them with a hygrometer, a scale, and a sound level meter. Throughout the testing process, we specifically filled these models with hard water to assess their performance accurately.

Our Top Picks

Best Overall
Honeywell Cool Mist Humidifier
Best For Plants
Taotronics AH-0001 Ultrasonic Humidifiers
Best Ultrasonic Model
Levoit Classic 300S Humidifier
Honeywell Cool Mist Humidifier
Taotronics AH-0001 Ultrasonic Humidifiers
Levoit Classic 300S Humidifier
Easy to use, Affordable, UV light for killing germs
Long-lasting, sleep mode, can set humidity at 95%
Top-fill, diffusion function, App control
Where to buy
Best Overall
Honeywell Cool Mist Humidifier
Honeywell Cool Mist Humidifier
Easy to use, Affordable, UV light for killing germs
Where to buy
Where to buy
Best For Plants
Taotronics AH-0001 Ultrasonic Humidifiers
Taotronics AH-0001 Ultrasonic Humidifiers
Long-lasting, sleep mode, can set humidity at 95%
Where to buy
Where to buy
Best Ultrasonic Model
Levoit Classic 300S Humidifier
Levoit Classic 300S Humidifier
Top-fill, diffusion function, App control
Where to buy
Where to buy

1. Honeywell Cool Mist Humidifier – Best Overall

honeywell cool moisture humidifier

Generally, evaporative humidifiers are more suitable than ultrasonic counterparts for hard water because they have wick filters inside to filter out the mineral substance.

This Honeywell humidifier is a popular evaporative model in the market and we found it is reliable, affordable, and easy to use after our tests.

I must admit, the size of this particular humidifier is a bit bulkier compared to ultrasonic models. But you can place it on the floor. Thanks to its evaporative technology, you don’t have to worry about the floor getting wet.

While it will not win any style points, the combination of white and light blue colors creates a subtle and unobtrusive look that can easily blend in with various decor styles.

This machine can adjust the output automatically according to the indoor humidity level. According to our test, the output under 45% humidity is around 189 ml, which is enough for covering a middle-sized room. 

Not only the wick can help with removing the mineral content in the hard water, but the UV light can also kill the bacteria.

However, it is important to note that you need to replace the wick every one or two months and UV light every 3000 hours of use, which can increase your maintenance cost.

This machine doesn’t have any fancy features. All you need to do is adjust the fan speed, which decides the output. 

We discovered through using this product that it has a downside that you may think is problematic – it doesn’t have an auto shut-off function. As a result, you need to refill it regularly. 

Coverage: 400 square feet (our estimation)

Water capacity: 3.79L

Output: 189 ml (based on our result)

Weight: 3.76 pounds

Warranty: 3 year

Size: 10.39"D x 18.58"W x 13.03"H

What we like  

  • Affordable place.
  • UV light for killing bacteria included.
  • Easy to use and clean.
  • Made with solid material.
  • 3-year warranty.

What we don’t like 

  • It is bulky.
  • It doesn’t have any additional features.
  • It can’t shut off automatically.
  • Extra cost on wick and UV light replacements.

2. Vornado EVDC500 Energy Smart Evaporative Humidifier – Best for Large Rooms

Vornado EVDC500 Energy Smart Evaporative Humidifier

This is another good evaporative humidifier that excels in handling hard water conditions. It features a clever design with wick filters positioned both on the front and back to remove mineral content from the water.

Different from the Honeywell one, this Vornado humidifier could be more suitable for large spaces due to its high output (250 ml) and water capacity (7.57L). The transparent water tank on each side makes the refilling process effortless.

Meanwhile, it has much more features. Rather than offering you a knob for changing fan speed, it has 3 built-in modes: low, high, and turbo. While the turbo mode is noisy, it can increase the humidity level much more quickly.

Based on our firsthand experience, the noise level in turbo mode could be as high as 62 dB, so it is definitely not a good idea to use it at night. The noise level on low mode is 49 dB, which is acceptable for most people.

Because it has a built-in humidistat, you can set it from 40% to 60% so that the room will never be over-humidified. Or you can set it to continuous mode.

One advantage of this model is that it features Energy Smart technology, which can adjust the fan speed automatically according to the indoor humidity level, allowing you to save more on electricity. 

We also like that it is extremely easy to clean. Each part can be disassembled easily so that you can clean up any mineral buildups with a breeze.

However, in addition to the little noise, the light on the side and display can’t be turned off when operating, making it not a great option for light sleepers.

Like other products from Vornado, it is made with durable material and has a 5-year warranty. However, it has a higher price tag, when compared to other models in this list.

Coverage: 1000 square feet

Output: 250ml (based on our result)

Water capacity: 7.57L

Weight: 8.9 lbs.

Warranty: 5 years

Size: 8.1 x 18.9 x 12.2 inches

What we like  

  • It can cover a space of up to 1000 sq. ft.
  • It has a built-in humidistat.
  • It features Energy Smart technology for saving more energy.
  • It has a 5-year warranty.
  • Very easy to clean. 

What we don’t like 

  • Cost on wicks. It requires two wicks to function well.
  • It is noisy for some light sleepers.
  • The light can’t be shut off.
  • High price tag.

3. Levoit Classic 300S Ultrasonic Top-Fill Smart Humidifier – Best Ultrasonic Model For Hard Water

levoit classic 300s humidifier

Many people assume that all ultrasonic humidifiers are filterless but it is not true. Some ultrasonic humidifiers make use of permanent or replaceable filters to purify the water to prevent clogs or white dust.

One such example is the Levoit Classic 300s, a popular choice from the trendy brand. Despite being an ultrasonic model, it incorporates a water filter to effectively capture impurities in the water.

What sets the Classic 300s apart is not just its filtration system but also its array of useful functions, making it exceptional among filtered ultrasonic humidifiers we have tested.

One notable feature is its top-fill design, which simplifies the refilling process. The generously sized opening on the top enables easy access to clean every nook and cranny of the humidifier.

With a substantial water capacity of 6 liters and an output of 256 ml, it is an excellent option for larger spaces. Additionally, it operates quieter than the two evaporative models I mentioned earlier.

Control options for the Classic 300s are versatile, as you can adjust settings both through the intuitive buttons on the front and via the Veync app. Yes, it is a smart humidifier! Through the app, you can set timers, choose operating modes, and even control the nightlight without leaving the comfort of your bed.

Furthermore, the humidifier features an aroma tray on the side, allowing you to enjoy additional benefits by using essential oils.

On a personal note, I particularly appreciate the sleep mode, which automatically turns off the nightlight and display. If you are a light sleeper, this feature will undoubtedly be a delightful addition to your nighttime routine.

We don’t find any visible downsides to this model. However, there is room for improvement in terms of price reduction and enhancing the accuracy of the humidistat.

Coverage: 505 square feet 

Water capacity: 6L

Output: 256 ml (based on our result)

Weight: 4.3 pounds

Warranty: 2 year

Size: 9.6*7.5*13.4 in

What we like  

  • Quiet operation.
  • You can control it through an APP or Alexa.
  • A specific sleep mode is included.
  • Top-fill design.
  • Diffusion function is included.
  • The filter replacement is cheap.

What we don’t like 

  • The price is a bit high.
  • The humidistat is not very accurate.

4. Taotronics TT-AH001 Cool Mist Humidifier – Best for Plants

taotronics AH-0001 humidifier

This Taotronic humidifier has maintained its popularity in the market for years and has become a favorite among many plant enthusiasts I know. They often use it for a few hours per day and have found that it is truly durable and not prone to breaking down when filled with hard water.

We were also impressed with this model during our testing. Despite its affordable price, it offers a plethora of fantastic features and performs flawlessly with hard water.

You can easily adjust the mist level, set the desired humidity level, control the nightlight, and even set the timer using the placed buttons on the front.

Whether your plants thrive in a humidity range of 30% or require a higher level of 95%, this humidifier has got you covered.

Additionally, it includes a sleep mode similar to the one found in the Levoit 300s. There’s also an Anion function, although we found it challenging to determine its effectiveness.

One of the standout features is its user-friendly operation, as each member of our team quickly grasped how to control it without needing to consult the instructions.

Moreover, the new version of this humidifier has introduced a WiFi function, allowing you to control it effortlessly through your smartphone.

While its appearance may not earn it high marks, its compact footprint enables it to be placed on any table with ease.

In terms of humidification performance, the 225 ml output is more than sufficient for adequately humidifying a medium-sized room. Even when operating in the highest setting, it remains remarkably quiet.

However, it is worth mentioning that the new version no longer includes a filter, which may potentially shorten the lifespan of the machine.

Coverage: 322 square feet

Water capacity: 4L

Output: 225 ml (based on our result)

Weight: 3.5 pounds

Warranty: 1 year to 1.5 years (if you register on their website)

Size: 8.1*5.3*11.8 in

What we like  

  • It is inexpensive.
  • Sleep mode included.
  • You can set the humidistat from 30% to 95%.
  • It is easy to control and clean.
  • The new version has a wifi function.

What we don’t like 

  • The new version doesn’t include a filter anymore.
  • The warranty is short.

5. MOVTIP Portable Small Snow Mountain Humidifier – Best For Travel

snow mountain humidifier

If you want to find a small humidifier that is portable and can work well with hard water to relieve your stuffy nose or sore throat, this Snow Mountain humidifier is a great option. 

In fact, since we have tested a few travel humidifiers, we discovered that the majority of them recommend or require the use of tap water.

This is primarily due to the design of the humidifiers, where the atomizer is positioned at the top. Manufacturers often advise against using distilled water in these humidifiers because the water droplets, if filled with distilled water, tend to accumulate around the atomizer, potentially impacting the mist output.

What makes this product stand out is that it has a relatively high output and pleasing design. The mountain-shaped top adds a touch of beauty, especially when the nightlight is turned on.

While the output may seem modest at 73 ml, it surpasses the performance of most travel models. With its 500 ml water tank capacity, it can provide up to 9 hours of continuous operation, making it highly suitable for your travel needs.

Coverage: 100 square feet (our estimation)

Water capacity: 0.5L

Size: 95*95*129mm

Water Capacity: 500ml

Output: 73ml in continuous mode / 50ml/h in intermittent mode (based on our test)

Warranty: Not sure

What we like  

  • Beautiful mountain-shaped design.
  • Easy to clean and refill.
  • Higher output than its counterparts.

What we don’t like 

  • You need to replace the cotton stick inside.
  • It may get things around wet.

6. Vicks Nursery Vaporizer – Best Warm Mist Option

vicks warm vaporizor

One major concern when using a humidifier with hard water is the potential for white dust to be produced. If you want to eliminate this issue but are working on a budget, using a vaporizer is the ultimate solution.

Instead of using a diaphragm, it uses electrodes to heat the water. To ensure the electrodes function well, the water needs to be conductive and hard water has much better conductivity than distilled water.

That is to say, hard water is perfect for working with a vaporizer. Otherwise, you will need to add salt to it. 

This Vicks vaporizer has been popular on the market for years and has a low price tag. It doesn’t have any fancy features, but its 5.68L water capacity and 358 ml output ensure that it can cover a large room.

Honestly, the size of the item is a bit larger than what I had initially anticipated, and it appears to lack a convenient handle for easy carrying. In light of these observations, we would recommend utilizing a traditional water bottle for refilling purposes rather than placing the item directly under a sink.

Note that the water could be hot when the machine is running so you should place it somewhere that is hard to access by your kids. Even for adults, it is recommended to exercise caution and wait until the water temperature has sufficiently cooled down before handling it.

Despite its simplicity, the device does possess one noteworthy feature that we find appealing. It has a medicine cup and two scent pad slots on the top. You can add Vicks vapopad, vaposteam, or similar products into them to relieve your symptoms quicker or create a delightful ambiance. 

This vaporizer has a nightlight on the top, however, it can’t be turned off when the machine is on. 

Based on our experience, you should clean it regularly to remove the scale formed on the steam unit. If not, it can stop producing mist after a while. 

Output: 358 ml (based on our results)

Coverage: 800 square feet (our estimation)

Water capacity: 5.68L

Weight: 2.2 lbs

Warranty: 3 year

Size: 15 x 12 x 10 in

What we like  

  • It is affordable. 
  • It is suitable for large rooms. 
  • It can be compatible with scent pads and essential oils.

What we don’t like 

  • It doesn’t have a handle for easy carrying. 
  • The nightlight remains illuminated at all times.
  • It has the potential to cause scalds and burns.
  • High electricity consumption. 
  • The steam unit is hard to clean.

How Did We Test?

At first, we purchased all the promising humidifiers that can work well with hard water and then put them into a two-weeks test. 

During the test, we only fill these humidifiers with hard water to check if they can function well after two weeks. 

To conduct an objective analysis, our team employed advanced measuring tools for precise evaluations. These included a specialized hygrometer to assess humidification performance, a sound level meter to measure noise levels, and a scale to calculate the hourly output.

Do humidifiers work with hard water?

While we have selected six best humidifiers for hard water for you to choose from, we must emphasize that it is generally not recommended to use a humidifier with hard water.

The reason for this caution is that the mineral deposits present in hard water can lead to the production of white dust and boost the growth of bacteria and mold.

If you want to use hard water, you should ensure the water remains fresh and prevent excessive mineral buildup inside the machine

What kind of humidifier is best for hard water?

In general, when dealing with hard water, evaporative humidifiers tend to be a preferable choice compared to ultrasonic humidifiers. This is primarily due to the evaporation process, which doesn’t disperse minerals into the air. As you know, the diaphragm in ultrasonic models can break down the mineral into tiny particles. 

Most evaporative humidifiers are filtered and the filter can remove the impurities. 

But you can still find some appropriate models in the ultrasonic category. For example, the Levoit 300s  includes a filter for removing mineral buildup.

On top of it, small travel humidifiers that have an atomizer on the tap usually work well with tap water.

What to consider when buying a humidifier for hard water?

There are three crucial factors that we think you should pay more attention to when picking a humidifier for hard water.

Type of humidifier 

For a quick decision, choosing an evaporative model is the way to go. These models are generally free from white dust issues associated with hard water. However, it’s important to note that they can be noisy, bulky, and relatively expensive.

If you have a preference for an ultrasonic model, don’t worry! There are still suitable options available. You can search for models that offer compatibility with filters or demineralization cartridges, or look for ones with a spacious opening on the water tank.

Filter replacement cost 

Most models that are compatible with hard water utilize filters. Therefore, along with the product itself, you should also consider the cost of filter replacement. 

Typically, you need to replace the filter every one or two months. The wick filter for an evaporative humidifier can cost you around 4 to 5 dollars, whereas a filter for an ultrasonic humidifier is about 1 dollar.

Ease of cleaning 

Humidifiers filled with hard water become dirty much more easily, even with the help of a filter. 

As a result, we highly recommend you look for a model that is easy to clean. For example, an ideal humidifier should have a big opening in the water tank so that you can access every corner to remove any accumulated residue or mineral deposits.

Other important factors:

Aside from the three factors we just mentioned, you should also consider if the model has enough coverage, how long the warranty is, as well as how noisy it is. 

Sum Up

If you live in an area with hard water and you want to use it to fill your humidifier, you should pick a humidifier that is compatible with hard water. Failure to do so may result in the premature breakdown of the machine.

Honeywell cool mist humidifier  and Vornado EVDC500  are good evaporative humidifiers to consider with the latter being particularly suitable for larger rooms. But if you prefer an ultrasonic one, Levoit 300s  and Taotronic AH-0001 can be good choices. After all, most ultrasonic ones can’t work well with hard water for a long time. 

Last update on 2023-10-02 at 06:54 / Affiliate links / Images from Amazon Product Advertising API

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Liz Yang is the founder of Airsmartly. She has been working at home for a few years and realizes that the performance of the HVAC system plays such an important role in our life. She has tested a lot of products in person, like humidifiers, air purifiers, dehumidifiers, and ACs, and wants to share tips about using or troubleshooting these products with you. Her uncle is an HVAC expert with over 30 years of experience in the field, and often offers assistance when she is unsure how to handle a situation. He is also in charge of reviewing the articles on this site.