Please note that acryl polymer humidifiers such as the adorini deluxe premium humidifier can be filled with distilled water only. Therefore, the following explanations are only applicable for traditional sponge-based humidifiers.
The following two liquids should be used for filling sponge-based humidifiers:
- Distilled water (available in supermarkets, auto parts stores, pharmacies, etc.)
- Special solution consisting of 50% propylene glycol and 50% distilled water
Propylene glycol is a colorless innocuous liquid, which has two extremely favorable characteristics for its use in humidors. Firstly, the formation of mold as well as bacteria is actively prevented. Secondly, propylene glycol forms a thin layer on the surface of the humidifier, which absorbs humidity at humidity levels of over 70% and which emits humidity at humidity levels below 70%. In this way, the humidifier is self-adjusting and will automatically stabilize the humidity level at an optimum level of approximately 70%. It might take a few days in the beginning until the propylene glycol forms a surface layer and an optimal humidity level is reached.
Propylene glycol is also known as 1.2 Propanediol. However it should never be confused with ethylene glycol (often referred to as glycol)! The purity of the propylene glycol should satisfy drug and food safety standards.
Distilled water has an advantage over normal tap water in that it protects the humidifier against calcification and mold. Normal tap water contains minerals, which can clog the pores of the humidifier sponge. Additionally, normal tap water contains chlorine and bacteria, which might impact the aroma within the humidor and may lead to mold.