Subbed to this discussion as I am also interested in the subject. I got a Philips humidifier but I want to invest in a second preferably ultrasonic.

This is my first year with Caladiums and second with EEs. The main problem I have with overwintering plants indoors is fungus from over-watering. I use a humidifier for specifically for 'me' when the heat is on and the plants probably like it too. I would be careful with a lot of indoor humidity in one area. Especially with the aquariums there too. Legionnaires' disease likes that environment. Cool mist or ultrasonic humidifiers could leave a foggy film on indoor glass & mirrors but less so if you use distilled water. Warm mist uses a lot of electricity, can burn you if you are not careful, and calcium builds up in them quickly. Wick or evaporation types ones are the best I think but you need to keep some bacteriostat in the water at all times.

You make sense yeah, but as you mentioned we are concerned by the central heating that dries the air. Are you using a Vicks humidifier?

An AirCare 5D6 700 by Essick is what I use. Moisture from over-watering killed a banana tree I tried to overwinter indoors. Moisture from over-watering may have caused some negligible rot on some Alocasia calidora spikes overwintered indoors last year. So added humidity specifically for plants is not needed in my environment.

Thanks everyone! My husband had a hygrometer in the garage for his woodworking so I brought it in the house. We live in the rainy PNW so humidity is almost 70% today. I suppose I will just have to keep my eyes on it and see if as it gets colder and we run the heat if it dips too low. I feel like the aquariums keep the rooms little humid anyway because of the evaporation. But we will see. I have an ultrasonic humidifier upstairs in the baby's nursery, but I never thought about Legionnaires or anything like that. I was thinking about just making a humidity tray like people do for orchids... but what can I put in the water to keep it from growing bacteria? Hmmm. Thank you again everyone!

I have a couple of ultrasonic humidifiers (both for me and the plants) & the instructions say to wash them out with dish soap and warm water every week -- presumably for this reason! What I found online says you can't use Bacteriostat products with ultrasonic humidifiers, though, because they aerosolize the chemical and poison the room, but soap & water does the job just fine.

Cassandra, you may not even need a humidity tray against the heater if it turns out the aquariums + the ambient humidity are enough to keep the humidity above 50%. And if you do, you can make a "tray" out of a dishwasher-safe plate and be sure it gets run through once a week.

I keep the one humidifier I have running clean with soap and water. That's good to know about the bacteriostat. I wasn't sure if I needed to put that in the humidity tray if I used one, but I suppose you're right and if I just change the water and wash it consistently, it should be fine.... if I end up needing one.

Thank you again! :)