Best Humidifier for Hard Water

Best Humidifier for Hard Water

Choosing the right humidifier for you can be a tricky business. There are a couple of things to think about when you purchase a humidifier. Keep in mind that an evaporative humidifier is likely to work best with hard water as the water is drawn into a wick filter, while as many other types of humidifiers are filterless, which means that unwanted minerals can escape into the air.

You’ll also need to think about the space you would like to cover and its positioning in your home or business environment. There are a huge variety of humidifiers available so it’s important to think about how much you plan to use it and what type will work best for you. We’ve rounded up five of the best humidifiers for hard water to help you make the best choice without breaking the bank.   

Check out our buyers guide for more information on making the right choice for hard water and for some useful advice on what to look out for when choosing your humidifier.  

In a rush? Check out our top pick the Honeywell HCM350W Germ Free Cool Mist Humidifier. This compact, evaporative model is an ideal choice for hard water.

With a 1 gallon tank capacity, the Honeywell can run happily for up to 24 hours, making it perfect for use in bedrooms or other medium sized rooms. With three different comfort settings, the model is simple and convenient to use and modify according to your personal preferences.

The tank is sturdy and durable, and should be easy to clean, fill and carry thanks to its wide opening and large handle.   

  •     Evaporative technology – ideal choice for hard water
  •     1 gallon tank capacity 
  •     runs for up to 24 hours 
  •     3 adjustable comfort settings
  •     compact and lightweight design

Summary of reviews

Product name Water capacity (gallon)Color Dimensions (inches)Product link
Honeywell HCM350W Germ Free Cool Mist Humidifier White1white / Black17.9 x 9.37 x 11.4 inches
Vicks 1-Gallon Warm Mist Humidifier 1white7.9 x 12 x 14.3 inches
Vornado EV200 Evaporative Whole Room Humidifier1.5white9.1 x 18.8 x 10.2 inches

TBI Pro 6 Ultrasonic Humidifier 1.6 white15.2 x 8.8 x 8.7 inches
Aircare MA0800 Digital Whole-House Console-Style Evaporative Humidifier2.5 galwhite12 x 18 x 16.5 inches

Honeywell HCM350W Germ Free Cool Mist Humidifier White


First up is the Honeywell Germ Free Cool Mist Humidifier. Developed using evaporative technology, this is a great option for hard water. The 1 gallon tank capacity means that it can run for up to 24 hours, making it ideal for use in bedrooms or other medium sized rooms in the home.

This model is a cool mist evaporative humidifier that emits cool moisture out in the air and is suitable for any space. It is also a lightweight and compact model.

The Honeywell HCM350W has been developed to produce quiet invisible moisture so you can rest assured you won’t be disturbed by a noisy filter. There are also three different comfort settings on this one, so you can adjust the volume and level of humidity anytime according to your personal preferences. 

This model also utilises UV light technology, and ensures that the water is 99.9 % free of bacteria, mould, fungus, and viruses. The water enters the UV water path from the tank and passes under UV light. The unwanted elements get treated, and a clean, safe mist enters the room. 

You will need to replace the filters every now and then as it is an evaporative model, but the wick filters are readily available and easy to change. It is recommended that genuine Honeywell replacement filters are used as they have a Protec antimicrobial coating, which prohibit 99.9% mould growth. 

The tank itself is easy to fill, clean and carry thanks to its wide opening and large handle, and you should find it durable as it has been designed with break resistant materials. Choose from two stylish colours.


  • Runs for up to 24 hours
  • Quiet, invisible moisture
  • Comfort settings
  • Easy to fill, clean and carry
  • Honeywell is a prominent manufacturer of quality humidifiers and the Honeywell HCM350M is a quality product

  • Filters will need replacing regularly

Vicks 1-Gallon Warm Mist Humidifier


This warm mist option is another great choice for hard water, releasing up to 99% bacteria free mist into the air. The water is heated inside the unit itself, meaning that bacteria and germs are actively eliminated in the process.

Cold air is added into the stream before it is released into the air to ensure that the mist is not too hot. The Vicks humidifier also has a generous 3.8L tank, which can last up to 24 hours between filling, so is perfect for bedroom environments to purify the air efficiently while you sleep.

There are two different mist output levels to choose from, depending on the amount of moisture you want to add into the room to maximise your comfort. It is also compatible with scented pads containing essential oils that are available to purchase separately, which is a nice option to have.

The steam and humidity provided by this device offers relief from cough and congestion due to colds or allergies. As there is no filter on this one, you will need to rinse it often in order to ensure it performs well, but this shouldn’t be difficult as the tank has a broad opening to facilitate cleaning.


  • Produces 99% bacteria free mist
  • 3.8L tank capacity
  • 2 different mist output settings
  • optional additional scented pads

  • Will require regular cleaning

Vornado EV200 Evaporative Whole Room Humidifier


The Vornado EV200 humidifier works effectively in larger spaces, covering up to 700 square feet. Designed for hard water, the evaporative unit has a generous 1.5 gallon capacity.

One great feature of this humidifier is its intelligent humidification; it senses how much humidity and circulation is required to consistently maintain your ideal environment and makes any necessary adjustments automatically.

The Vornado design is easy to operate with simple controls and six output levels, allowing you to choose fan settings and manage your preferred humidity levels.

The SimpleTank system also allows for quick and easy cleaning; the tanks pop out and the caps are easily removable. You may need to think about its positioning during the night as it does emit some light. Replacement wicks are available online.



  • Simple and easy to use
  • Intelligent humidification makes it a great hassle free option
  • Six output levels

  • Light may disturb sleep

TBI Pro 6 Ultrasonic Humidifier


The TBI Pro works really well for larger spaces with a large 6L tank and powerful engine, generating a full two days of use. This is definitely the one to go for if you’re looking for something that can cover a big space. The 360˚ rotating nozzle produces uniform humidification and the direction is easy to adjust according to where you need it most.

There are 3 adjustable mist settings, which ensure an even level of humidity and create a comfortable, balanced environment in your home. This design is also fitted with a medical stone filter, which purifies the water to ensure that the mist output is free from any bacteria or impurities.

Arguably one of the best features of this one is its ‘Whisper-quiet’ sleep mode, which modifies the system to silent operation and turns off all indicators when activated, all with minimal noise levels.

The TBI Pro also features a convenient timer, allowing you to regulate the period of time you want the humidifier to be active for, and it will automatically shut down when this period ends.


  • Efficient on energy
  • Perfect for bigger rooms
  • Minimal maintenance

  • It’s a bit heavy

Aircare MA0800 Digital Whole-House Console-Style Evaporative Humidifier


Finally, we have the Aircare MA0800. This is a great option if you’re looking for something simple and easy to use. The evaporative technology is perfect for hard water and works effectively to maintain humidity levels.

This model has 3 speed motor settings and an optional quiet night-time setting, which is always handy to have. Energy efficient and cost effective, the Aircare will automatically shut down when your desired humidity levels have been reached or when the tank is empty.

The tank also has a spring valve rather than a cap, so re-filling is an easy and manageable task. You will also be able to monitor the humidity levels through the day on the digital display, giving you the option to adjust the settings whenever you want.

Again as with many other evaporative models, you will need to replace the wick filters fairly regularly, (handy indicators will let you know when it’s time to top up or change) which can be costly over time, but you will likely find the improved air quality justifies the expense, as many consumer reviews have noted.


  • Easy to assemble
  • Easy to manage and operate
  • Evaporative technology ideal for hard water
  • 3 easily adjustable speed motor settings
  • Optional quiet night-time setting makes it ideal for bedroom areas

  • Filters will need changing frequently which can be expensive


Best Humidifier for Hard Water Buying Guide

There are considerable benefits from the use of humidifiers in your living space or work environment, which include helping respiratory problems and keeping your skin from drying out. Medical research also shows that healthy humidified air can help you fight coughs, colds, allergies, dry skin, insomnia and nosebleeds.

However, there are issues with the operation of humidifiers in hard water areas. Hard water contains various minerals that produce higher levels of calcium and magnesium than soft water, this can lead to white dust deposits in your rooms and can be the cause of respiratory problems. Furthermore, the deposits will block up the humidifier.

One solution is to use distilled water which does not contain the damaging minerals, but this is expensive and a better solution is to choose an appropriate device that can deal with the issue directly.

If you’re looking for a humidifier that can function effectively with hard water, you will want to look at models with an evaporative filter, as minerals can build up on the parts that are exposed to water on a filterless design, meaning that the humidifier can break down quickly.

Models with high-quality filters and descalers can safely eliminate up to 99% of contaminants, making them an ideal choice. 

Before you purchase a humidifier, you will need to consider its primary function in your home, and think about its positioning in your living space. Some humidifiers can be noisy, so it’s a good idea to look at models that offer a quieter ‘sleep mode’ or adjustable motor settings if you think the potential noise may bother you.

If you’re looking at positioning your humidifier in a bedroom area, also bear in mind that some devices emit some light when in use which could disrupt your sleep. 

Another thing to think about is the size of the area you are looking to cover. Some humidifiers cover less area than the manufacturer states, so it may be a good idea to consider going for a larger size humidifier than you think you need to ensure it is effective.

Remember that whole house humidifiers will only work well if doorways are kept open at all times so the air can circulate around freely. Most humidifiers will need to be refilled once every 24 hours or so, so if you plan to use it continuously or through the night, think about opting for a model with a larger capacity to accommodate your needs. 

Some humidifiers also have a humidistat that senses the humidity in the room and shuts the machine off when it reaches the right level, which is a really handy feature that is worth looking out for to save time and reduce electrical energy levels.   

Best Humidifier for Hard Water FAQ’s 

How often should I clean my humidifier? 

It is advisable to clean your humidifier at least once a week in order for it to perform effectively and prevent any mineral build up or residue.

For safety, be sure to unplug the device before you start. Empty, rinse and dry the tank as often as possible. Clean out any mineral build up or residue and rinse carefully. Check the filters frequently for signs of wear or potential blockages. 

Are humidifiers beneficial to health?

Humidifiers work to add moisture to the air to prevent dryness and reduce irritation. They can be beneficial for reducing dryness of the skin, nose, throat and lips. They can also help alleviative cold or flu symptoms.

They are often used to relieve symptoms such as dry skin, cracked lips, nose irritation, headaches and sinus congestion. However, overuse of humidifiers can cause problems so it is important to be mindful of your usage. 

Should I choose cool mist or warm mist? 

Humidifiers produce either warm or cool air to reduce dryness. Both types have pros and cons. Cool mist humidifiers require less electricity than warm mist, and may be a safer option for use around young children.

However, they can be noisy as they use fans to cool the water down and propel the water into the air. Warm mist humidifiers tend to be a bit quieter and work really well in smaller areas. The boiling process itself can also help to eliminate waterborne mould and bacteria, but they will require more electricity to function.

How often will I need to replace the filters on my humidifier?

Many evaporative cool mist humidifiers will require replaceable wick filters that will need to be changed every couple of months on average, but this does depend on how often you use it and the mineral content in the water.  If you are using hard water, it is a good idea to change the filter more frequently, ideally every month or so.

This is because mineral deposits can clog filters faster and can produce white dust if the filter is not changed regularly. Remember to ensure that your replacement filters match the humidifiers name and model number, as filters can vary widely.

Replacement filters are widely available online or direct from your manufacturer, and are also often available at hardware stores or supermarkets. 

What are the main different types of humidifier? 

There are five main types of humidifier; central humidifiers, evaporators, impeller humidifiers, steam vaporizers and ultrasonic humidifiers.

Central humidifiers are usually built directly into your home’s heating or air conditioning unit. These are typically expensive to fit but they’re often the best and most practical option if you are looking to add humidity to your entire house.

Evaporators work by blowing moisture through a special moistened filter. Fans then expel humidity into the room from the system, making them a good choice if you plan to use the unit in one room at a time.

Impeller humidifiers operate by using a number of rotating disks that run at very high speeds, creating a cool mist that fills the air.

Steam vaporisers are usually a fairly inexpensive option, and are often widely available to purchase.

Electrically powered, these humidifiers heat water and then cool it before expelling it safely into the air. Steam vaporisers may not be the most practical choice around young children as they can be dangerous and cause burns if not handled with extreme care.

Finally, Ultrasonic humidifiers produce a cool mist using ultrasonic vibration. Widely reviewed, they are often a popular choice and are available in both cool mist and warm mist varieties.