After weeks and weeks of solid 70/70 hygrometer readings overnight my humidity spiked to 75%. There were no changes to the humidor, no changes to its placement, no addition or subtraction of anything inside. The temp is still rock solid at 70. The hygrometer will lower to 70% when I open the humidor for a little while which makes me wonder if the hygrometer is actually messed up (my first suspicion). I know I can re-calibrate it and I may do that but just wondering if anyone had any other ideas? Thanks

Beads.

Kitty Litter.

you using a swamp cooler to cool your house?

Don't sweat the small stuff. I only check the humidity when I get something out of the Humidor (which isn't that often).

calibrate

Using Hearfelt Beads and the humidor is in my office which is temperature controlled at 70 degrees 24/7. I may just recalibrate and see what happens. I really hate doing that, LOL.

Setting up the cal takes about same amount of time as making a post here. Reading it the next day takes even less time. Not trying to be a smartass, but you suggested you suspect the hygro - seems calibration would be first thing.

This is the way I knopw how to do it. You have a different method as this takes longer than a post and I don't find it extrememly reliable. If you use Boveda packs it takes even longer:

To calibrate your hygrometer you will need table salt, a see through container such as a Ziplock baggie, and a small shallow open container, like a bottle cap.

Place a teaspoon or so of salt in the shallow container and add a few drops of water to get it wet. You don't want to dissolve it, just get a good damp pile of salt in your container. Remember, you don't want a salt water solution, just damp salt. Place the shallow container in the baggie along with the hygrometer.

Seal the baggie with some air trapped inside (so it is not tight against the hygrometer) and let it sit. Allow this to stabilize for at least 6 hours (don't rush it). After it has stabilized, check the hygrometer reading without opening up the baggie. It should be exactly 75%.

If your hygrometer doesn't read 75% after calibration then you have 2 choices. First you can remember the deviation of your hygrometer. If it read 80% then you are 5% off and have to subtract 5% from whatever it reads. The second option is to adjust the hygrometer if your model allows for this. Some hygrometers have a dial on the back or side that can be turned to adjust the unit to 75%. If yours doesn't have this, then go with option 1.

I would take my backup hygrometer and place it inside with the other before trying to fix anything.

If it is easy for you to go by and pick up a 70% Boveda, I suggest you do that and just put any hygrometers in there, double baggie for good seal.

I calibrated my two digital ones by the salt method a week or so ago. Then, when I recently decided to go from 70% to 65%, I saw where someone recommended you calibrate at the actual RH you were using. Went by local B&M, picked up a Boveda 65% ( checked date of manufacture) set the digital hygrometers I had just calibrated in there overnight - hey, got 68%.

These little $15 cheaply made things do a great job for the money. But, they are not linearly accurate, in my experience.

Everybody has their preferences. I have been at 70/70 for a number of years. Reading here and searching around, I decided to go to 65/65.

YMMV

Dunno where he lives, but I live in South Carolina. Even with the air on, I am at 80% in my home. Lot of rain, flooding even, overcast days keep the A/C from running as much as normal.

Hell, I open the wineador, the hygrometers start climbing!

When I dropped down to 65/65 from 70/70 recently, I had to put dessicant bags from the gun safe inside to pull the humidity down.

I use crystal clear Kitty litter placed in a dollar store nylon knee high stocking....perfect 70 %. Have to mist them about very 3 weeks with distiller water. I'm in Florida so before using these my 'dors were in the high 70's at times, The litter will also pull out humidy as well as add humidity. I use digital Xicar hygrometers, run about $20. I have had no problems since using the kitty litter, I have had one 'dor going over 3 years with the same stocking full at a constant 70 %.

Doc