These 4 Humidifiers Can Handle Hard Water & Don't Leave That Annoying White Dust

Dehumidifier with touch panel, humidity indicator, uv lamp, air ionizer, water container works at ho...

Hard water does a number on everything from your kitchen appliances to your hair, and it makes simple purchases like a humidifier especially complicated. If you’re in the market for something that’s supposed to add moisture to the air, you must take into account hard water’s high mineral content. The best humidifier for hard water will be an evaporative cool mist model with a wick filter. Keep reading to learn why this type of humidifier wins out — and for my top product picks.

Evaporative Vs. Ultrasonic

To take a step back, there are two main types of humidifiers: ultrasonic and evaporative. While ultrasonic models are popular for being extra quiet, they aren’t good humidifiers for hard water since they are generally filterless (which means unwanted minerals can get into the air). Ultrasonic humidifiers work by using vibrations to create a microfine mist (along with the minerals in it), which creates that infamous “white dust” associated with humidifiers. An evaporative humidifier, on the other hand, draws water into a wick filter, which helps trap those minerals, and then a fan blows the water vapor through to disperse.

Warm Mist Vs. Cool Mist

Warm mist or cool mist are other humidifier terms you've probably encountered on your search for the perfect model. For hard water, cool mist humidifiers are the way to go for one simple reason: they’re easier to clean. A warm mist humidifier (sometimes called a vaporizer) has an additional heating component to deal with and leaves behind more mineral deposits in the tank. A cool mist humidifier has the additional benefits of requiring less energy to operate, since it doesn’t heat up, and is approved for safe use around kids and pets, too.

These are the four best evaporative cool moisture humidifiers on Amazon. They're sized for every type of room, and one of them can even tackle a whole house.

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The Overall Best Humidifier For Hard Water

Featuring evaporative technology, this cool mist humidifier has amassed legions of fans (think 6,000+ Amazon reviews). It's designed for medium-sized rooms with a one-gallon capacity that runs for up to 24 hours without needing a refill. The removable tank comes with a wide opening, making it easy to fill and to get inside and clean thoroughly. This humidifier earns bonus points for boasting UV technology that kills over 99% of bacteria. Since it's an evaporative model, it does use wick filters that will eventually need to be replaced (replacements can be found here), but you can take comfort in the fact that they're catching the mineral deposits found in hard water. "Sure, you have to change filters regularly, but it doesn't over-humidify your room or force whatever's growing in your tap water into your air," one shopper noted.

This pick is available in two different colors: a sleek black and an airy white.


An Easy-Fill Humidifier That Can Cover Larger Rooms

Another great humidifier for hard water, this evaporative unit has a 1.5-gallon capacity that covers up to 700 square feet. The brand's SimpleTank system was designed for ease of use: you can pop out the two tanks for simple top-filling, and the wide opening lets you scrub from any angle when it's time for a clean. The tank lids screw on securely and feature a built-in handle that’s a thoughtful addition for easy carrying. It features three different fan settings with six humidity output levels, and the signature "vortex action" circulates comfortable air at every level of your room. While it's technically not a "cool mist" humidifier, the air that is circulated is cool. And when it comes time to change the filter, replacement wick filters come in a twinpack so you have a backup.


The Best Humidifier For Kids

This compact humidifier, with a fun projector night light, has an antimicrobial filter that traps up to 95 percent of bacteria for a germ-free cool mist. It's an evaporative model that's designed for medium to large rooms. Plus, it's compatible with therapeutic Vicks VapoPads that create a soothing menthol-infused mist for additional relief for when your child is sick. Its one-gallon tank will last through the night (it can run on low for up to 24 hours), and there's an automatic shut-off if you accidentally leave it on. It has a wider opening on the bottom to refill the tank — although the tank doesn't detach, shoppers reported it's still pretty easy to clean. "Love this humidifier! It makes some white noise that is perfect. Does not leave any white residue from hard water," one review noted. It comes in two color options: blue and pink. And you can grab these extra water filters while it's on your mind.


A Large Humidifier For Your Whole House

This extra-large evaporative humidifier boasts a four-gallon tank capacity that can operate on full blast for up to 24 hours of cool moisture and cover 1,000 square feet. Three fan speeds and a built-in humidity control let you dial in your preferred settings, and its intelligent sensors monitor the ambient humidity and adjust accordingly to maintain just the right balance. The twin removable no-leak, spill-proof tanks have built-in handles for easy carrying and filling. The tanks do have pretty narrow openings, so you can’t reach inside, but reviewers were satisfied with how relatively easy it was to clean them. Pick up a two-pack of replacement wick filters here.