humidifier on the table at home

To protect you and your family from the dangers of mold spores, learn what to put in humidifier to prevent mold with our guide here to prevent your home from these hazards.

Humidifiers are a great asset to any home because they will raise the humidity levels and make the air more comfortable. People with respiratory conditions like asthma, emphysema, chronic bronchitis, and pneumonia can find relief in the fresh, moist air a humidifier curates.

But where there is water, there can be mold. If you allow your humidifier to develop mold, it may disperse mold spores into the air as it sprays. Mold spores in the air can worsen respiratory conditions and even cause them if you inhale enough mold.

Risks of Mold in Humidifier

When mold grows in your humidifier, whether in the sprayer, the tank, or another part, it damages your health and the comfort of your home. Mold and mildew love to grow in wet places, and your humidifier is one of the wettest appliances in your house.

Long-term mold exposure can result in serious health problems like insomnia, memory loss, trouble concentrating and confusion, depression, anxiety, muscle cramps, numbness in extremities, weight gain, light sensitivity, and hair loss.

Mold is not something to be taken lightly, so to protect you and your family from these detrimental effects of toxic mold, follow this guide to care for your humidifier.

what to put in humidifier to prevent mold
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What to Put in Humidifier to Prevent Mold

To prevent mold from growing in your humidifier and entering your home’s air, you need to add some sort of antibacterial or antimicrobial agent to neutralize bacteria and stop mold growth.


Adding a capful of bleach to your humidifier’s water will eliminate the possibility of mold growth. Bleach kills bacteria thoroughly, so you don’t need to worry about mold spores spraying into your air.

Don’t use more than a teaspoon or two of bleach in your tank because bleach is harmful to humans as well as bacteria. If you add too much, it will spray high quantities of bleach into your air, and breathing in bleach is not a good idea.

Hydrogen Peroxide

Hydrogen Peroxide is another chemical that neutralizes bacteria and will stop the growth of mold. Just a teaspoon inside your humidifier’s water tank will prevent mold. Hydrogen peroxide is an antifungal and antibacterial solution that is inexpensive to keep around.

White Vinegar

Add a whole cup of white vinegar to your humidifier’s water tank, and its antifungal and antimicrobial properties will prevent mold growth. White vinegar is cheap, and most people already have it around their kitchen, so this is one of the more convenient solutions for mold in your humidifier.

Humidifier Tablets

If all of this sounds too DIY for your liking, they make tablets that keep your humidifier mold-free. All you have to do is drop one in every time you fill-up the tank with water. The tablets are sold at most grocery stores, so they’re easy to find, although they can be a bit pricey.

Teatree Oil

Teatree oil is antifungal, antibacterial, and antiviral, so it works similarly to hydrogen peroxide to prevent mold. It also can aid in breathing for those with respiratory conditions like asthma. Just add a handful of drops to your tank whenever you change the water.

Humidifier Maintenance Tips

Change Water Daily

It may sound annoying to change your humidifier’s water every single day, but it is necessary to keep the humidifier clean and properly working. Water can collect bacteria over time and becomes stale. You always want the water in your humidifier’s tank to be as fresh as possible, so change it daily and use distilled water for best results.

Clean Regularly

The key to a clean humidifier and healthy home is to clean your unit regularly. Don’t skip any weeks, and make sure every cleaning is cleaned thoroughly. Missing spots or neglecting the humidifier will result in mold, which is terrible for you and your family’s health.

Close Doors and Windows

Keep the doors and windows closed in the room where you keep your humidifier. This keeps the moist air from dispersing too much. If you try to use a relatively small humidifier to raise the humidity levels of a whole house or apartment, you will likely be disappointed by the results and your humidifier will work overtime and possibly overheat.

If you want to raise humidity levels throughout a whole house, you should purchase multiple humidifiers to place throughout the home. Another option is whole-house humidifiers, which are more expensive and work slightly differently can be very effective.

Bottom Line

If you use a humidifier to increase your home’s humidity levels, these tricks can help you keep the air fresh and clean, and mold-free. Using bleach, white vinegar, hydrogen peroxide, Tea tree oil, or humidifier tablets are all easy solutions to mold that grows in humidifiers.

Don’t let your useful appliance turn into a mold factory. Follow this simple guide to keeping your humidifier in tip-top shape so you can breathe well and be healthy.


What can I add to water for a nice smell?

Fresh lemon slices or a squirt of lemon juice can add a fresh citrus smell to your home’s air. Fruit can cause mold, so make sure to clean the tank regularly if you plan to do this.

You can also add a few drops of essential oils to moisten the air with a pleasing scent and improve air quality. Essential oils are used in aromatherapy and can foster a tranquil mood inside your home.

How quickly does mold grow?

It only takes 24-48 hours for mold to develop in a moist location. This is why it is so important to change your water daily and clean the tank frequently. Luckily, using any of the substances mentioned above can stop mold and mildew from developing altogether.