What to put in a humidifier to prevent mold

Low humidity levels in the air are the leading reason why most people suffer from allergic reactions when staying indoors for a long time. Some of these allergic reactions include dry skin and lips and breathing problems.

Specialists propose using humidifiers to increase and maintain the required humidity levels. It will help alleviate the allergies caused by dry air in your home.

Even so, humidifiers use water and heat; this creates the best environment for mold growth.

Molds infestation will not only affect the performance of your humidifier but can also lead to further health problems when molds are dispersed into the air.

Poor maintenance of humidifiers is the main reason why mold may infest. With proper maintenance practices, you can prevent mold invasion in your humidifier. Here is a discussion about avoiding mold infestation in your humidifier.

What Is A Humidifier?

It is an electronic device used to increase humidity levels in a room to the normal ranges.

The device achieves this by adding moisture content into the air, making the air warmer and comfortable to inhale.

The appliance is invaluable to people who suffer from asthma and allergies, including nasal congestions.

Reasons Why Mold Grow In Humidifiers

Mold loves humid and warm areas; this is the environment inside a humidifier’s water tank. Some of the early signs of mold growth are vivid white, green, brown, or black patches on your humidifier’s internal surfaces.

Lack of changing the water in your humidifier tank at least after two days of continuous usage can lead to mold and bacteria breeding.

The more you prolong using the same water in the humidifier, the higher the chances of a mold infestation in the device.

The type of water that one uses in a humidifier can also contribute to mold growth in the humidifier. While most people find tap water as the most convenient to use, tap water is not suitable for humidifiers.

Tap water is rich in minerals and bacteria; these minerals can lead to residue buildups in the tank.

While the bacteria can trigger mold in the humidifier, the minerals are a good food source for mold hence encouraging them to breed.

Poor maintenance practices. Cleaning a humidifier once in a while is not the proper way of maintaining it. Humidifiers require frequent cleaning exercises to avoid the growth of bacteria and mold.

Signs That Your Humidifier Has Mold

A moldy humidifier can lead to several health complications, which should alert you that mold is present in your device.

When a humidifier has mold, it will spray out water vapor with tons of mold spores. Here is what you are likely to experience;

  • Flu-like symptoms coupled with excessive coughing reduced when the humidifier turned off.
  • For asthmatic victims, they may notice an increase in asthma attacks and respiratory issues.
  • Healthy people in the house may start complaining of shortness of breath because of poor air quality resulted from the moldy humidifier.
  • Eye and skin irritation, among others.

Besides the health effects, a moldy humidifier may give your house a foul smell. Mold spores may start breeding on surfaces such as furniture, towels, and walls.

It is, therefore, essential that you learn how to prevent the growth of mold in your humidifier.

What To Put In A Humidifier To prevent Growth of Mold

Preventing mold in a humidifier should not be a challenging task. There are several additives that you can add to your humidifier water tank. Read on to learn more.

  1. Tea tree oil

You can stop the mold growth in your humidifier by adding five or six drops of tea tree oil to the humidifier water.

It’s a natural disinfectant besides being an essential oil. The oil comes from Melaleuca Alternifolia, commonly found in Australia.

The tree possesses antiviral, antibacterial, and antifungal properties.


  1. White Vinegar

White vinegar has antibacterial and antimicrobial properties that will eliminate and prevent any mold growth in your humidifier.

You can either use it as a cleaning detergent or an additive to your humidifier water tank.

For cleaning purposes, use a 1:1 ratio of vinegar to the water.

As an additive, you can add a cup or two of white vinegar to the humidifier water, preventing mold growth.

You can do this mixing when the humidifier is running.

  • Humidifier Tablets

Humidifier tablets are manufactured to prevent mold growth and the buildup of lime in a humidifier.

You can buy the tablets from online stores or your local store even though the price may be higher than natural additives.

Buy the tablets and drop one in the humidifier’s water tank, that all. Drop one pill in the water reservoir each time you refill the reservoir.

The tablets can also prevent bad smells.

  1. Hydrogen Peroxide

Hydrogen peroxide is one of the cheapest additives you can use to prevent mold in your humidifier; as an antibacterial and antifungal, it will kill bacteria and mold.

You only require few drops or half a teaspoon of hydrogen peroxide in the reservoir tank whenever you’re filling it with water, and your humidifier will be free from mold.

  1. Use Distilled Water

If you want to prevent mold from growing in your humidifier, you should avoid using tap water on the device.

You can spare yourself from using other methods of stopping mold infestation in your humidifier by settling for distilled water as the water to put in your appliance.

Distilled water does not have bacteria nor minerals, hence no breeding mold.

Other ways of ensuring your humidifier are free from mold are by:

  • Cleaning it regularly
  • Changing the filters periodically
  • Storing the device in a dry place whenever it is not in use
  • Following the manufacturer’s maintenance advice


Humidifiers are invaluable devices in homes that experience dry and arid air. These devices will increase the moisture content in your home’s air, which will relieve you and your family members from the harshness of dry air.

However, since humidifiers use water, mold is likely to form; this may impair the device’s performance and lower the quality of air in your home.

Essential oils such as tea tree oil are good in preventing mold growth. Other additives include hydrogen peroxide, white vinegar, and humidifier tablets.

Having few drops of the additives or a tablet in the water reservoir whenever you fill water in your humidifier will prevent mold in your humidifier.

Good maintenance practices and the use of distilled water will also stop the mold from infesting in your humidifier.




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