What Is The Black Stuff In My Humidifier?
Many people use humidifiers to solve a problem with dry air in their home. It's a great solution, unless you find something concerning in a humidifier. So, what is the black stuff in my humidifier?
The black stuff in your humidifier could be mold, scorched mineral deposits, or biofilm, all of which can be problematic. A humidifier’s heating element can burm mineral deposits if you have hard water. Otherwise, the bacteria, stagnant water, and warmth in a humidifier are likely to cause mold and biofilm to form.
Many people throw their humidifier away immediately after finding black gunk in the tank. This is fair, but it’s only necessary if the black stuff remains no matter how much you clean the tank. Follow along as we explore what the black stuff in your humidifier is.
Why Is There Black Stuff In My Humidifier?
If there’s black stuff in your humidifier, it’s most likely biofilm, which is also the black gunk that you may find in your bathroom sink or shower drain. This collection of microorganisms typically appears in consistently moist environments. That’s why many people mistake biofilm for mold, which can also grow in a humidifier. In some cases, people find biofilm, mold, and mineral buildup in their humidifiers.
That’s especially true if you have hard water, as it can leave mineral deposits behind. You’re more likely to find biofilm and mold in your humidifier if you don’t clean it routinely. Stop running your humidifier right away when you discover black gunk, as it can be dangerous, whether it’s mold or biofilm.
Biofilm
A humidifier tank is the perfect breeding ground for biofilm because it typically holds stagnant water for hours, even when in use. This device slowly vaporizes water over 8-12 hours, or for however long you run it. During this time, the tank stays damp and bacteria, dust, and contaminants will build up over time. Depending on your water quality and humidifier tank size, biofilm can form within 3 days.
That said, it doesn’t usually grow as aggressively in humidifiers as it does in shower drains because drains are full of soap scum, dead skin, and hair. Regularly clean your humidifier tank once or twice weekly to prevent biofilm from forming.
Mineral Deposits
Do you put tap water in your humidifier? If you it's hard water, there’s a good chance you’ll find black gunk in the tank. Most mineral deposits are white or light gray, but they can sometimes appear black or dark gray. They can become darker when biofilm is present, and they can worsen one another. Stop running your humidifier if you have hard water, as it can irritate your lungs.
Evaporated hard water can also leave a chalky residue on nearby surfaces. Avoid these problems by filling your humidifier tank with demineralized or distilled water. Reverse osmosis water is another great option. Your humidifier will perform better if you stop putting hard water in the tank.
Mold
A moldy humidifier is dangerous for many reasons. Evaporating moldy water can release mold spores into the air, which can travel throughout your home. Once mold appears in your humidifier, it will likely stay unless you take serious action. The tank is a common hot spot for mold due to the heat and moisture present.
Organic matter and impurities in the filter can also contribute to mold in a humidifier tank. Some people clean their humidifier tanks without ever replacing the filter, which is a big mistake. Many manufacturers recommend replacing a humidifier’s filter every 1 to 3 months. That, paired with regular cleanings, will prevent mold from growing in the tank.
Scorched Flakes
Humidifiers contain elements that heat and evaporate the water in the tank. Impurities and mineral deposits in the tank can cling to the heating element and burn. In that case, the black stuff in your humidifier may be burned mineral flakes or other scorched contaminants. A portable humidifier’s heating element typically runs at 180 to 212 degrees Fahrenheit.
That is more than enough to burn limescale deposits and leave black flakes behind. Sometimes, a harsh smell accompanies this, but you may not be around to notice it. There’s nothing you can do about this problem besides taking preventative measures. Clean the humidifier tank with distilled white vinegar 1-2 times weekly to remove mineral deposits and refill it with distilled water.
Is Biofilm Dangerous?
Biofilm is dangerous, especially when it’s in a humidifier tank. A humidifier evaporate water and releases the mist into the air, which can circulate throughout your home. When biofilm is present, that mist contains bacteria, contaminants, and other impurities. These impurities can travel far, especially when your air conditioner or furnace is running.
This is essentially no different than tainted water coming from your showerhead when the pipes are full of biofilm. The only real difference is that humidifiers can take these impurities further, especially if your home has great airflow.
Legionella is a harmful bacterium sometimes found in humidifiers, and it can cause Legionnaire’s disease, which in extreme cases, can be fatal. Always fill your humidifier with clean water.
Should You Throw Away A Moldy Humidifier?
You should only throw the humidifier away if mold remains after deep cleanings. However, some people understandably pitch their moldy humidifiers right away out of fear. This makes sense considering how dangerous black mold is, especially if you have asthma or COPD. If you want to clean a moldy humidifier, wear a protective face mask.
A respirator is the best option, but a cloth face mask is better than nothing. That said, you must use your best judgment after cleaning the humidifier tank. Just because there are no signs of mold doesn’t mean it’s not there. In that case, you’re better off sniffing the tank to see if it still smells musty and moldy. However, that can be dangerous, so you must weigh the pros and cons and decide whether getting rid of the humidifier is the best option.
How To Clean A Moldy Humidifier
1. Prepare The Unit
Before you clean your humidifier, turn off the unit off, wait a second, and then unplug it from the wall. Dump any remaining water out into the sink, then remove the water tank.
2. Treat With Vinegar
Distilled white vinegar is easily the best household remedy for stains, clogged drains, and moldy humidifier tanks. It contains acetic acid, which is powerful enough to clean many stubborn stains. The trick is to mix equal parts warm water with distilled white vinegar. Pour the mixture into the humidifier tank and shake it without spilling.
Set a timer for 20 to 30 minutes and let the vinegar and water sit. Rinse the tank with hot water for a minute or until it no longer smells like vinegar. Keep in mind that you may need to clean the tank with vinegar a few times before the mold is gone. This can be frustrating, but it’s better to take your time than to throw out the humidifier.
3. Use Hydrogen Peroxide
If you don’t have any luck with white vinegar, you can clean the humidifier tank with hydrogen peroxide. Ideally, look for 3% hydrogen peroxide, as a weaker concentration won’t work as well. Fill a container with 1-2 cups of hydrogen peroxide and 4 cups of water for the best results.
Pour the diluted hydrogen peroxide into the tank and leave it for 20 to 30 minutes. Then scrub the tank with a brush and thoroughly rinse with hot water. YBe careful and make sure no hydrogen peroxide remains, or else you can’t safely run your humidifier again.
Summing It Up
The black stuff in your humidifier is likely biofilm or black mold. Biofilm is essentially a colony of microorganisms found in humidifier tanks, bathroom sinks, and shower drains. Humidifier tanks are prone to mold and biofilm due to the stagnant water, heat, and organic matter. Hard water can worsen the problem and damage your humidifier.
Related Guides:
Nick Durante is a professional writer with a primary focus on home improvement. When he is not writing about home improvement or taking on projects around the house, he likes to read and create art. He is always looking towards the newest trends in home improvement.
More by Nick Durante
