Lab Notes

✶ May 3, 2026 ✶

My husband got sick and blames the humidifier. Is he right??

New Humidity: The Witch and the Homewrecking Humidifier

My poor husband was a bit under the weather. We tried to figure out where he'd been, who he was in contact with that may have been sick too, what he had eaten, etc. Eventually, we kinda just gave up and decided to deal with the cold-like symptoms are they presented themselves. This somehow turned into a blame game against the humidifier in the bedroom. Living in a desert, the air a tad dry and really messes with your skin, hair, and respiratory system, so we use this 24/7. It may, or may not, had been a while since it was cleaned out. (If my dirty sink from the previous post is any indicator, I need to hire a housekeeper...). And so, this post is about testing it!

Experiments: Swift 380T Microscope @ 400x & 1000x magnification

Organism	Observations	Photos
"Pink Mold" from bottom of humidifier Serratia marcescens	I was pretty bad about the pictures this post... I didn't get much, but there was a 1.2" patch of pink, soft, damp "mold" at the bottom of the machine. This is what we're testing since the rest of the machine parts looked fine from the naked eye. We have a couple things to consider before deciding what the bacterial player is. One, the dark, damp, and cool environment breeds just about every imaginable THING on the planet, so we've done the opposite in narrowing it down. Also, the machine is always filled with tap water. It should be distilled, but I'm not exactly made of money. What we do know is that there was a A LOT of biofilm, and lots of larger microbes, as well as bacteria in the shapes of: diplococci, diplobacilli, and even some palisades. I'll attempt to isolate these next time to narrow down what we're looking at... Personally, I find the palisades one quite fun since we get a lot of the others in the finidings. And would you look at that! According to the CDC it's actually an airborne bacteria, not a fungus. It's the same pink stuff you find in your shower/tub/sink if you don't clean it regularly. The humidifier in this case was simply aerosolizing this bacteria in the air, which is known to cause respiratory illness (my husband's issue), wound infections, and UTIs! so to cap up the question: yeah, it was most likely the humidifier at fault. Next on our tour is the second image. The baby bacteria behind the larger object in the center shows how much bigger it is in comparision. But what I found very interesting was that it appears to be ungoing binary fission - one of the final stages of cell division. It's an asexual method of reproduction, and it can be done by bacteria, protozoa, and certain algae. But... what this is specifically, I have no idea... Now, about the funky bear-like thing in the last image? I was excited thinking I found something awesome. It's not... it's probably a phytoclasts, which is just fancy plant fragments. Since our tap water is originated from the Truckee River, it's just harmless plant matter. Cleaning tips: Fill the water tank with a mixture of water and white vinegar or a bleach solution. Let it sit for 20-30 minutes to kill existing bacteria.

Organism

Observations

Photos

"Pink Mold" from bottom of humidifier

Serratia marcescens

I was pretty bad about the pictures this post... I didn't get much, but there was a 1.2" patch of pink, soft, damp "mold" at the bottom of the machine. This is what we're testing since the rest of the machine parts looked fine from the naked eye.

We have a couple things to consider before deciding what the bacterial player is. One, the dark, damp, and cool environment breeds just about every imaginable THING on the planet, so we've done the opposite in narrowing it down. Also, the machine is always filled with tap water. It should be distilled, but I'm not exactly made of money. What we do know is that there was a A LOT of biofilm, and lots of larger microbes, as well as bacteria in the shapes of: diplococci, diplobacilli, and even some palisades. I'll attempt to isolate these next time to narrow down what we're looking at...

Personally, I find the palisades one quite fun since we get a lot of the others in the finidings. And would you look at that! According to the CDC it's actually an airborne bacteria, not a fungus. It's the same pink stuff you find in your shower/tub/sink if you don't clean it regularly. The humidifier in this case was simply aerosolizing this bacteria in the air, which is known to cause respiratory illness (my husband's issue), wound infections, and UTIs! so to cap up the question: yeah, it was most likely the humidifier at fault.

Next on our tour is the second image. The baby bacteria behind the larger object in the center shows how much bigger it is in comparision. But what I found very interesting was that it appears to be ungoing binary fission - one of the final stages of cell division. It's an asexual method of reproduction, and it can be done by bacteria, protozoa, and certain algae. But... what this is specifically, I have no idea...

Now, about the funky bear-like thing in the last image? I was excited thinking I found something awesome. It's not... it's probably a phytoclasts, which is just fancy plant fragments. Since our tap water is originated from the Truckee River, it's just harmless plant matter.

Cleaning tips: Fill the water tank with a mixture of water and white vinegar or a bleach solution. Let it sit for 20-30 minutes to kill existing bacteria.

Location of sample

Humidifier

Humidifier didn't ask for this.