5 Best Humidifiers for Hard Water (Recommended by a Renowned Water Treatment Engineer)

Finding the best possible solution for low-humidity is my forte, and that is to use a humidifier. However, when it comes to determining the best water to use for your humidifier is a whole different line of expertise.


If you have heard about hard water you might think that there’s something going on inside the solution that may be harmful to health or not suitable to use. I don’t want to base my post on my limited knowledge about hard water so I decided to talk to an expert.


And, who better to ask than a Water Treatment Engineer! I recently had a fun and overwhelming interview with Antonio Morgan, who is an engineer at the proposed Houston’s Water Purification Plant (which will, by the way, the biggest facility of that sort in the world!).

His tips and insights about hard water are excellent plus he recommended the best humidifier for hard water.
Here’s what he had to say:


One on One with A Water Treatment Expert

Leona Maurer: First of all, I would like to thank you for taking the time to answer a few questions, I am sure my readers will appreciate it!

Antonio Morgan: Thanks for having me, it will be my pleasure to help out.

Leona Maurer: Sure thing! Well, to start with, could you tell us what is Hard Water exactly and what differs it from normal water?

Antonio Morgan: Good question Leona! Perhaps, you may have heard your friends say “My water at home is hard” Basically, hard water is normal water, but with a few additions such as dissolved minerals, mainly calcium, and magnesium.

Leona Maurer: I see, Is such water a health hazard?

Antonio Morgan: Not exactly since those minerals are components of the water. However, if you have hard water at home, washing clothes would be a little challenging because it counteracts your detergent. The same with taking a shower, you’ll notice that your soap does not make enough bubbles.

Also, some of your appliances such as the washing machine, humidifier, and dishwasher may have accumulated mineral build-ups which can, later on, shorten their lifespan. Faucets, sink, and bathtubs will also show build-up and discoloration due to hard water effects.

Leona Maurer: How do calcium and magnesium end up dissolved in the water in the first place? Does air pollution have something to do with it?

Antonio Morgan: You bet! When the air is rich in carbon dioxide the water becomes acidic and then makes it an excellent solvent. Now, as the water goes through rock and soil, small amounts of minerals dissolve including hard minerals calcium and magnesium, and create a solution that we know as Hard water.


Leona Maurer: Wow, we really should take care of the environment then! Thanks to professionals like you. But, is there a way that we can test our own water supply at home?


Antonio Morgan: That’s why we do our very best to keep the water supply at the most convenient level. You see Leona, the more magnesium and calcium there are, the harder your water would be.

There are quick tests you can perform to check your water supply, I recommend the DIY Testing for 10 Different Contaminants or, you can try the DIY Testing for 20 Different Contaminants if you want to be really sure the water you use is hard or safe to drink for that matter.


One of my personal home testing kits, the Test Assured 10 Minute Testing, is for testing the water for Lead Bacteria, Pesticide, Iron, Copper. But, it also detects more mineral components including magnesium and calcium.

Leona Maurer: Thank you for the tips. Now, my main concern for this interview is how we can use hard water in humidifiers?

Antonio Morgan: The truth is, hard water may harm your humidifier, especially those units tagged as “no filter”. Using hard water in your humidifier will produce white dust and cause build-ups in the water tank.

You see, build-ups will shorten the lifespan of your appliance, and the white dust can cause health hazards especially if you have allergies and asthma.

Apart from that, the accumulation of white dust emitted from the humidifier will destroy the surrounding furniture and flooring.

Leona Maurer: ​​​So what do you suggest the best humidifier for hard water would be?

Antonio Morgan: Well, I can't simply tell you "The best humidifier for hard water is this model". There are many humidifiers that can work great in such conditions.

But, what I would recommend is to choose a humidifier that has either a filter or is based on the evaporative process and have a wick filter.

Models with high-quality filters and descalers will eliminate 99% of contaminants. This includes calcium and magnesium.

On the other hand, the wick filter humidifiers will keep everything "stuck" in the wick filter. Either way, both humidifier types are quite suitable for hard water use.

Leona Maurer: I see, so you mean to say that ultrasonic and impeller types won’t be suitable for hard water since they don’t have filters, right? ​​​

Antonio Morgan: You can definitely use ultrasonic and impeller types Leona, as long as the specific unit you own has a feature to combat white dust and build-up. There are recent humidifiers that work perfectly with hard water using demineralization cartridges.

Leona Maurer: Well that’s excellent then, do you have a set of humidifier features that would work best for hard water? A list maybe?

Antonio Morgan: Haha sure thing! I do have a list of some of the notable humidifiers that completely works with humidifier regardless of their operating type.

Best Humidifier for Hard Water - The Expert's List

I was so glad Antonio shared his recommendations. Here are the top 5 of the best humidifiers for hard water:

Best Humidifier for Hard Water (Expert's Choice #1) - Elechomes Ultrasonic Humidifier

Specific Features (Click here to know more)

This humidifier is a combo of cool and warm mist with a modern interface. It’s ultrasonic yet it has a filter to trap impurities in the water and that includes using hard water.


You no longer need to worry about having a hard water supply, you simply have to replace the filter as recommended.

Although the filter is built-in, if necessary, you can replace it after two or three months of use or depend on the accumulation of mineral build-ups.


Elechomes humidifier can hold up to 6 liters of water which runs 40 hours of continuous use and a mist coverage of up to 750 square feet.


And, thanks to an inbuilt humidity sensor, it won’t actually run all the time. It shuts off automatically when the desired humidity is reached and keeps monitoring the humidity levels and turns back on if needed.


Best Humidifier for Hard Water (Expert’s Choice #2) - Taotronics Ultrasonic Humidifier 4L

Specific Features (Click To Know More)

The first thing I have to highlight with this humidifier is the Microporous Filter Cartridge system. The cartridge is ideal for those who have a hard water supply at home. 


Apart from managing hard water, the cartridge also blocks microorganisms and bad odor-causing bacteria. 


Mind you, having a hard water supply is not an issue with this humidifier! Furthermore, this is a large-capacity humidifier that can store up to 4 liters of water and runs up to 30 hours of continuous use on a low-mist setting.


Taotronics is known for keeping indoor humidity levels automatically with an intelligent humidity monitoring operation. 


This humidifier is likewise easy to clean and maintain, thanks to the cleaning brush that’s included in the box, plus the built-in handle is super helpful when it comes to refilling and cleaning the unit. 


You can clean the unit on a weekly basis or depend on the dirt and calcium build-up. It also has a 360° nozzle setup which makes the room well-hydrated. 


Overall, Taotronics is a perfect home partner especially when the air is too dry and the water too hard. 

Best Humidifier for Hard Water (Expert’s Choice #3) - Pure Guardian Ultrasonic Humidifier

Specific Features (Click here to know more)

Silver has long been used as antibacterial and has been integrated into so many applications today and one of the most interesting is its integration with humidifiers. 


Pure Guardian Ultrasonic Cool Mist Humidifier highlights its Silver Clean Protection feature to avoid slimy bacteria growth and mineral build-up. 


Because of this, it is a certified germ-free humidifier that ensures no harmful bacteria gets into the air you breathe. 


This unit runs whisper-quiet making sure that you get a good night’s rest and decked with a night light and multiple mist control. To make the room more relaxing, you can add aromatherapy oils to lighten the ambiance.


Refill is simple since it’s top-fill and has an indicator to let you know when it’s about to run out of water. Maintenance is also a breeze since it utilizes silver, you don’t have to spend more time and energy brushing off build-ups, well, depends on how hard your water is. 


But, overall, this model is perfect for this season and for hard water reasons!

Best Humidifier for Hard Water (Expert’s Choice #4) - Honeywell Cool Mist Humidifier

Specific Features (Click here to know more)

Honeywell HCM710 is an evaporative type of humidifier that stays true to its tagline Easy to fill, use, and clean.


This unit works pretty upfront and has few yet outstanding features. Because it has a wick filter, you can practically use any water types, especially hard water. Although you need to change or clean the filters on a regular basis and this means, depending on the build-up you are seeing at the tank.


For better hard water protection, you can add on Protec antimicrobial cartridge which also kills mold growth and bacteria.


You can achieve ideal indoor humidity for 36 hours under the lowest mist setting and by filling the 3.7L water tank. It also shuts off automatically when the water is running low to avoid overheating the unit.


However, the only thing that you need to consider about this unit is the noise, since it is an evaporative type, but, nevertheless, the noise is not that much impacting and is equal to the noise your air conditioning unit emits.

Best Humidifier for Hard Water (Expert's Choice #5) - Honeywell HCM350B Humidifier

Best Humidifier for Hard Water - Honeywell HCM350B Humidifier

Specific Features (Click here to know more)

If you are looking for a go-to humidifier, the Honeywell HCM350B is the ideal choice. It uses an evaporative technology that utilizes a wick filter to ensure that water impurities and hard minerals are extracted before misting into the air.


Apart from the wick filter system, this model comes with UV technology that kills all the germs and bacteria in the water.


It runs up to 24 hours on the lowest setting and consumes 3.7L of water on a single refill. This unit has a manual dial knob set up in a user-friendly manner. You can also opt for a demineralization cartridge for added protection and longer device lifespan.


Cleaning and maintenance requirements are at least once a week and filter replacement depend on the severity of hard water.


Even though it runs on an evaporative wick-type, this cool mist humidifier boasts of its quiet operation and close to invisible moisture.


The best part about getting an evaporative humidifier is that there is no fear of over humidifying the room since it keeps the humidity between 40-60%

So Which One Is The Best For Hard Water?

Antonio may have been very generous to give us his top 5 humidifiers for hard water but there should be only one that would absolutely stand out.


Among these 5, the best choice goes for the Honeywell HCM350B. The main reason for choosing this unit is its ability to operate in any water conditions, even hard water. It also supports adding cleaning balls to further clean the water apart from the wick filter.


If you are all about protecting your overall home value, you can also make distilled water on your own so you don’t have to endure hard water on your humidifier.


I personally would like to thank Antonio for his comprehensive insights about hard water and for the tips on how to resolve it in using the humidifier. Hard water is actually a result of our irresponsible behaviors towards the environment and in the end, we still suffer the consequences.


Fortunately, there are people like Antonio, who have dedicated their lives to making sure we all get a safe water supply.


His top five list for the best humidifiers for hard water could greatly help us in choosing what unit to use especially for those living in areas with a hard water supply.


Remember, his recommendations are on a general basis and if you are having severe hard water issues, it is still best to consult a local water treatment engineer in your area so they can check and identify the solutions.

6 thoughts on “5 Best Humidifiers for Hard Water (Recommended by a Renowned Water Treatment Engineer)”

  1. Hi, I’m a working mom with 3 kids and I was thinking if honeywell HCM 350 humidifer is a good fit. When I searched online, there were mixed reviews about this ”germ-free” humidifier. Is it possible to do a review on this humidifier?

    • Hi Carol, thanks for a good question. Yes, I’ve also seen mixed reviews but honestly, I truly believe that the bad reviews come from people who don’t take care of their humidifiers. By taking care, I mean regular cleaning, washing the wick filter, and regular wick replacement. This really is a great humidifier that will keep all the impurities from the water stuck inside the wick filter, and, the UV light model also kills germs. As for the review of this model, I will actually test this model out and let you know my thoughts in the future!

  2. Hi Leona, I really loved this post and enjoyed reading it. Just wanted to ask you something. I was planning on buying the Vicks Ultrasonic Cool Mist Humidifier, but then I started doing some research and it turns out that people are complaining about the condensation on the outer surface of the tank and that it creates a watery mess around the humidifier. Would you by any chance do a review of that model? I would love to hear your thoughts on it. Thanks in advance and keep up the great work!

    • Hi Anna. Thanks for the nice words and I will try and keep up the good work. Now, as for the Vicks humidifier, I’ve also heard a lot of complaints, and I promise I will look into it. In fact, I know a fellow mommy blogger who already has one so you will get your Vicks impressions post sooner than you thought 😉

  3. Thanks for the thoughtful, fun article! I’ve gone through a lot of the Vicks-style models, the heating elements corrode in my water. Didn’t think of using distilled water, but that sounds pricey! As are wick filters – I read a review on Amazon that said they need replacing every 6 weeks and they cost over $5 each. Replacing burnt-out humidifiers costs more. Thanks for your tips, hopefully I can get a machine that works for us in Canada,

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