Humidor Setup: How to Use Activator Solution
Activator solution is simply a combination of propylene glycol and distilled water in a 50/50 mixture. The reasons why activator solution is used over regular tap water are numerous. The main reasons however are that tap water may contain contaminants which cause odors and foul tastes and it is harder to control mold. Activator solution helps prevent cigars from molding and also helps maintain a 70% environment in your humidor.
Using activator solution is very simple. Place your humidifier on a table with a cloth underneath it. Open the activator bottle and squirt some solution into the humidifier. You don't want to drench the humidifier, but rather make it nice and wet. Shake off the excess liquid, wipe clean with a cloth and place back into your humidor.
This procedure should be repeated when your cigars start to get dry or when your hygrometer reads the humidity as being lower than you prefer.