Vornado - EV100

No, when water evaporates (which is what’s happening with the steam in the shower), it doesn’t take the particulate matter with it. Ultrasonic humidifiers are not evaporative. Fwiw, there ARE evaporative humidifiers on the market that you can use tap water with instead of the ultrasonic ones. We have a Vornado evaporative humidifier, and it’s fantastic.

Vornado. We have the EV100 model. You can set the desired humidity level and it will maintain it for you.

Vornado, their shit is next level and built to last.

I love my Vornado evaporative humidifier. It works well and is easy to clean.  

I love my Vornado Evaporative humidifier 

There is no such thing as a maintenance-free humidifier, whether it’s evaporative, ultrasonic, or even steam, they all require regular cleaning or regular changing of filters (or sometimes both). Steam is less prone to mold, but also super hot, and is prone to scale buildup which still requires cleaning. I would suggest giving your current unit a thorough clean first to see if that solves the issue. We have a 6L LEVOIT (ultrasonic/cool mist) humidifier, and I check ours every couple of weeks. If I see the mold, wipe the affected areas down with vinegar and rinse. Hydrogen peroxide 3% works well if I really want to feel thorough. We also make sure to change out the filter as recommended or more often (you can buy them in bulk). We also run two Vornado evaporative humidifiers on the first floor of the house. Let me tell you, the wicks in those develop considerable mold, and we change them out once a month or sometimes more often. Regardless of humidifier the concept is the same. You have to take care of them no matter what you buy.

Evaporative humidifiers are the only choice unless you're going to actually use distilled water. You do need to replace the wick as it gets filled with minerals and stuff grows on it, but easier than dealing with airborne mineral dust or baked on minerals. Use a humidifier treatment solution and the wicks last significantly longer. I currently use a combo of a vornado and best air golden solution.

Evaporative humidifiers. Pros: don't need distilled water(although probably makes the wicks last longer), no hard water dandruff like ultrasonic. Cons: need to replace wicks relatively often, should use a bacteriostatic water treatment I'm using a vornado one I bought from costco, but there are probably better ones out there.

I have several Vornado EV100s in my house and I love them. They are evaporative, so you need to buy a new wick every season, but they are insanely low maintenance outside of that and the easiest to clean I've ever experienced. 

I guess I should clarify in that we run ours daily from basically mid November through end of February, and a wick lasts the full time. Manual says every 4-8 weeks, but going our full ~16 week season doesn't cause us any issues.

This is my biggest issue with any sort of humidifier that is barely smart enough to turn it itself off when it runs out of water. They always leave a “mold pool” in the bottom to remind you to clean them out. We have a super cheep vornado that could care less if it has any water. You gotta check it every few days. But it has never grown any mold. 

vornando brand evaporative humidifier is the best i've used - i've had probably 15 different humidifiers over the years. this one is easiest to use, easiest to maintain, and maintains the lowest possibility of putting mold into your air. It also is the easiest to fill without spilling water anywhere. I do not trust the "steam" type, i had one nearly burn down my house a number of years ago - anything with a heating element should not be running 24/7, especially if you are not home.. never trust the built in humidistat. use a separate hydrogometer placed close-ish to the bass. adjust the unit to turn on/off based on what it's reading near the instrument. a laminate bass would likely be fine, but maintaining 45% or so humidity is nice regardless of basses.

I live in New England, relative humidity falls a lot in the winter and fret sprout and cracking can happen if guitars aren’t kept in a more humid environment. My guitars are on stands in my office, in the winter I keep the room doors closed and use a Vornado evaporative humidifier, it has a built in humidity sensor and keeps the RH consistent pretty reliably (I’ve got a separate RH sensor to double check and they both tend to show similar readings).

Aircare or Vornado EVAPORATIVE models. Uses a pad (that you need to replace or heavily clean with a vinegar soak every 1-2 months) but uses regular tap water and creates no dust. I have 2 Aircare console (aka large) units keeping 2800 sq ft at 35% humidity.