I recently purchased a 25 cigar humidor off of cheapcigarhumidors. It came yesterday and reading the instructions, it told me to put a shot glass full of water along with the humidifier in the humidor. I did that and then followed the directions for calibrating the hydrometer. When I slipped it in the bag it registered 57% humidity and when I woke up this morning it read 59% humidity. I left it in there until noon today and it registered the same so I turned it up to 75% and took it out of the bag to see if it would go down. It went down slowly but not by much, right now its at like 72% sitting in my dry house. I went to walmart and picked up a digital hydrometer and thermometer for $6.50 just to check this one. The package said it could be +/-5% humidity in its reading, is that okay? Now should I salt test this digital one even though its non changeable?