And for you Techno-Buffs:
The tube is the delivery system for the water vapor. It is a special grade of space age clear plastic which has microscopic pores in the walls. Even though you can't see these pores, they allow water vapor through, something like a permeable membrane. In fact, this plastic was developed to keep blister cards from sweating on the inside while in an air conditioned store by allowing the water vapor to pass through. The process of humidification that keep your cigars fresh actually occurs through the walls of the tube, not the holes in the cap. Water vapor will permeate through the walls of the tube, but the liquid will not. This allows you to place the DryMistat® right next to your un-celloed cigars.
Crystals keep the liquid from coming out through the cap. They are like space age super sponges. They soak up liquids up to 100 times their own weight. One pound of Crystals can soak up 25 gallons of water. You may have seen something similar to them used in baby diapers or the plant industry. They get larger when they soak up this liquid. As the water evaporates, the Crystals get smaller. This is the reason we use them. It gives you a visual indication of when it's time to add water. No more guessing when the unit is drying out. When the volume of the crystals significantly decreases in the tube, its time to add water.
Hydra-Crystal are actually a space age plastic polymer. The technical name for them is super absorbent potassium polyacrylate. They act like sponges, but that's where the similarity ends. The absorption of water actually occurs at the molecular level. To simplify the explanation, we need to envision a single polymer crystal as containing many billions of very long "springs" which can be both stretched and relaxed. As the water molecules come in contact with this "spring", it stretches to surround it. As the water vaporizes and leaves the bond, the spring comes back to it's original compressed state. This expansion and contraction can occur hundreds of times before the crystals become "used up". This represents many years in the life of this product, even if rehydration were to occurs every 2 weeks.
Please notice we have NOT used the term distilled water in our specs. There are no pores to clog and therefore plain tap water is all that is needed. If there was an extreme amount of mineralization in the tap water, all that would happen is the deposits on the spring may prevent them from fully closing, thereby reducing the maximum effective life from 10 years down to 5.
We have initially charged your DryMistat® with special chemicals and water to automatically regulate the relative humidity inside your humidor to 70%. You may have seen solutions marketed as balancing liquids to add to the Credox style of humidistats. These chemicals are relatively safe and nontoxic. They are actually the same as those used in cosmetics and Easter egg dyes.
Contained within the super absorbent polyacrylate crystals is a mixture of 50% propylene glycol and 50% water. The water contained within the crystals will vaporize and release moisture into a closed container like a humidor. Water alone can theoretically bring the relative humidity as high as 95%. The propylene glycol is a hydrostatic liquid which absorbs moisture when the relative humidity goes over 70%, thus helping to stabilize the mini-environment created within our humidor. As long as there is more than 50% propylene glycol present, the humidity should not go over 70%. Please note, the DryMistat® started at 50% water and 50% propylene glycol. The water evaporates but the propylene glycol does not and the ratio is always over 50%.