How Bad Is Tap Water for Humidifiers, Really?

Tap water may be the easiest option, but it's not always the best. Here's why tap water shouldn't be used for ultrasonic humidifiers, but why you can use it for evaporative humidifiers.

Why You Shouldn't Use Tap Water in Your Humidifier

Tap water may contain minerals such as calcium, magnesium, and potassium. If used in an ultrasonic humidifier, these minerals will become teeny-tiny particles in your air and can leave a thin white film on surfaces.

Tap water can also cause mineral buildup, or scaling, inside your humidifier. This creates a breeding ground for microorganisms, such as bacteria and fungi—things you don’t want in your water or air. That's why it's important to regularly descale your humidifier tank and pour out leftover water before each refill.

When You Can Use Tap Water in Your Humidifier

If you don't fancy the idea of filtering or buying distilled water, we've got good news for you. The Levoit Superior 6000S Smart Evaporative Humidifier uses elevated wick filters to capture minerals and large particles, which means you can refill the tank straight from the tap. Additionally, the helpful Dry Mode feature uses low and high fan speeds to dry out the filters, helping to prevent moisture buildup and mold.

Sources

Use and Care of Home Humidifiers | US EPA

Dirty Humidifiers May Cause Health Problems - CPSC Publication 5046