If the humidity in the humidor is too high, one might do the following:
- Ensure that the hygrometer was calibrated according to the salt solution method, that the humidifier was filled with a propylene glycol solution (when using sponge-based humidifiers) and that the inside of the humidor was sufficiently moistened before its first use.
- Only for sponge-based humidifiers: If the propylene glycol solution has not been refilled for a few months then it might be time to refill the humidifier with the propylene glycol solution.
Deviations of a few percentages from the 70% mark should not be of major concern and one should also consider the explanations regarding the accuracy of humidity measurement (See hygrometer accuracy).