Ron: I have three humidors. I do not use the humidifier at all during the summer and only in part of the fall. When I used the humidifier I was getting readings of 85% humidity; without the humidifier 72-75%. I tested the hygrometers by putting them all in the same humidor and by leaving them on the kitchen counter. They all read about the same.
To keep the humidity down I have been opening the lid at times when the outside humidity is lower. I have also taken small ceramic space heaters and directed them at the open humidor.
Finally, I have set the open humidor in a closed room next to a dehumidifier. All these methods bring the humidity down, but once I close the lid the humidity returns to the high level.
GK: My guess is the humidifier/s are made to handle a much bigger humidor than those you have. I would suggest either using smaller humidifiers, or do what I do: add a teaspoon of distilled water when they need to be recharged instead of completely refilling them. If that’s not enough add a little more. If it was too much, let it dry out a bit; then you have an even better idea as to the amount of distilled needed to keep proper RH.
Ron: The humidors are about 2, 6, and 9 years old. The newer ones seem to retain more humidity. All the cigars (approx. 225) are fine, neither dried out our moist.
GK: Thankfully, the cigars are OK. In addition to the suggestions above, here’s one more idea that I picked up from a customer a while back: Add a small jar filled with white rice to the humidor to absorb the extra moisture. Restaurants in beach areas and similar locales where the weather is always a little damp, add rice to their salt shakers, which prevents the salt from caking up. Give it a try.