The Kind of Water to Use in a Humidifier Made Easy

When choosing water for your humidifier, distilled water is generally considered the best option. It’s free from minerals and contaminants that can lead to scale buildup, bacterial growth, and the production of white dust in your home.

Distilled water is what I recommend because it helps maintain your humidifier’s efficiency, extends its lifespan, and ensures the mist produced is clean and safe to breathe. While it may be more expensive than tap water, the benefits often outweigh the cost.

If distilled water isn’t available or feasible, demineralized or filtered water can be good alternatives. These options remove many of the minerals and impurities found in tap water, though not as thoroughly as distillation. Tap water can be used in most humidifiers, but it may lead to more frequent cleaning and maintenance, especially in areas with hard water.

Regardless of the type of humidifier water you use, it’s crucial to clean your humidifier regularly and follow the manufacturer’s recommendations to ensure optimal performance and maintain good air quality in your home.

Key Takeaways

  • Alternative water options in order of preference:
    • Demineralized water
    • Filtered water
    • Reverse osmosis water
    • Tap water (least recommended, especially in hard water areas)
  • Water choice impacts:
    • Mineral buildup and scaling
    • Filter lifespan
    • Mist quality and output
    • Energy efficiency
    • Maintenance requirements

5 Types of Water Available for Humidifiers

  1. Tap water
  2. Distilled water
  3. Demineralized water
  4. Filtered water
  5. Reverse osmosis water

The Impact of Water Type on Humidifier Performance

  • Mineral Buildup and Scaling – Hard water, rich in minerals like calcium and magnesium, can lead to scale deposits in your humidifier. This buildup can reduce efficiency and potentially harbor bacteria.
  • Filter Lifespan – Mineral-rich water can clog filters faster, necessitating more frequent replacements.
  • Mist Quality and Output – Purer water generally produces a finer, more consistent mist.
  • Energy Efficiency – Scale buildup can force your humidifier to work harder, consuming more energy.
  • Maintenance Requirements – Some water types may require more frequent maintenance than others.

5 Types of Water for Your Humidifier

Distilled Water in Humidifiers

Distilled water is widely considered the best choice for humidifiers which is why I use it. The effectiveness of filtered water depends on the type and quality of the filter used. While not as pure as distilled or demineralized water, a good filter can remove many contaminants and reduce mineral content, which is why I recommend it over tap water.


  • Very pure, with minerals and contaminants removed
  • Distilled water lacks the minerals that can accumulate in your device, preventing the formation of scale and white dust.
  • Often recommended by humidifier manufacturers
  • The absence of minerals and impurities makes it harder for bacteria to thrive.
  • With less buildup and contamination, your device will likely last longer and require less maintenance.


  • More expensive than tap water

Demineralized Water in Humidifiers

Demineralized or deionized water is another excellent choice for humidifiers. This water undergoes a process that removes most minerals and ions, though not as thoroughly as distillation.


  • Reduces scale buildup and mineral buildup
  • Cheaper than distilled water


  • Not as pure as distilled water
  • May still contain some contaminants
  • Pricier than other options

Reverse Osmosis Water in Humidifiers

Reverse osmosis systems force water through a semipermeable membrane, removing most contaminants and minerals.


  • Very pure water, similar to distilled
  • Removes most contaminants and minerals


  • Requires installation of a reverse osmosis system
  • Can be wasteful, as reverse osmosis systems discard some water during the filtration process

Filtered Water in Humidifiers

Filtered water can be a good middle-ground option for your humidifier. Water filtered through pitcher filters which is what I use, faucet-mounted systems, or whole-house filtration can be a good middle ground.


  • Removes some contaminants and minerals
  • More cost-effective than buying distilled water


  • Effectiveness varies depending on the filter type and quality
  • May not remove all minerals

Tap Water in Humidifiers

The suitability of tap water for humidifiers varies greatly depending on your location and local water quality. In areas with soft water, tap water might be acceptable for humidifier use. However, in regions with hard water, using tap water can lead to several issues.


  • Convenient and readily available
  • Cost-effective


  • High mineral content in many regions
  • Contains chlorine and other additives
  • This can lead to white dust and mineral buildup
  • Minerals in tap water can provide a breeding ground for bacteria and mold.

Making Distilled Water for a Humidifier

To make distilled water for a humidifier, you will need to buy or build a still. Water distillers can be purchased online, or if you prefer to make your own still. When using any still, always follow safety guidelines, as the process involves high temperatures and steam.

Special Considerations for Different Humidifier Types

  • Cool Mist vs. Warm Mist – Cool mist humidifiers may be more susceptible to bacterial growth, making water purity more critical.
  • Ultrasonic Humidifiers – These are particularly sensitive to water quality and may produce more white dust with mineral-rich water.
  • Evaporative Humidifiers – While generally less affected by water quality, they still benefit from cleaner water for optimal performance.
  • Essential Oils – If you use essential oils in your humidifier for aromatherapy, it’s crucial to use distilled water to prevent any interaction between the minerals in other water types and the oils.
  • Hard Water Areas – If you live in an area with particularly hard water, investing in a water treatment system or consistently using distilled water becomes even more critical for your humidifier’s performance.
  • Baby Rooms and Nurseries – For humidifiers used in baby rooms, it’s especially important to use the purest water possible to ensure the best air quality for your little one.


An overlooked route of inhalation exposure to tap water constituents for children and adults –

Joel Simon

Joel, a seasoned blogger with a passion for home products, has been making waves in the digital realm for the past seven years. With a knack for crafting insightful reviews and informative posts, He has become a trusted voice in the world of home improvement and lifestyle blogging.

Recent Posts