Maintaining your Humidor
Add distilled water to your humidifier when the relative humidity begins to dip. After the humidor has been stabilized, this dip should occur slowly and steadily... 69%, 68%, 67% and so on. Typically, I add distilled water when I hit 64% or so. Remember DO NOT saturate the Credo, but only moisten it! This is the biggest error most new humidor owners make. Keep in mind that a Credo not only raises the humidity to 70% RH, but it also lowers the humidity when it exceeds this level. Therefore it is essential that there is room left within the Credo's volume to absorb the excess moisture if necessary.
Only use distilled water. Tap water has chemicals and minerals that you do not want in contact with your cigars as they age. Also, tap water contains organics and is prone to developing mold. Distilled water is the only readily available water that is free of both mineral and organic impurities.
Do not be anal retentive about the RH humidity. Any number between 64% and 72% is fine; truth is, every cigar smokes differently. Some will be best at 68%, while other less-tightly-rolled cigars will burn better at 72%. Some people like their cigars even drier and try to keep them closer to 60%. Ignore what everyone tells you about 70/70 and experiment with slightly drier and wetter humidity levels until you find what you like best. Personally, I prefer 65%-67% RH as the ideal relative humidity.
Temperature control is not nearly as critical as the humidity. Any temperature between 50-75 degrees is fine. A couple of notes though; at the lower temp, the aging process slows down, while at the higher temp, the hatching of the dreaded tobacco beetle is a potential risk. More importantly, always keep your humidor out of the sunlight - being bathed in the sun's rays drastically escalates the internal temperature within the box. Also, never place it on a television set or near a stereo system, as any such electronic device will generate considerable heat.
Totally DISREGARD any table or advice explaining that the ideal humidity for storing your cigars changes depending on the temperature. This is a myth that sadly has been published in some otherwise respectable publications. It is based on the principles of absolute moisture content and not relative humidity. 70% relative humidity is 70% relative humidity regardless of the temperature (hence the term "relative").