I was having this same issue, trying to get my humi to 70/70.. but I finally realized, after reading the numbers I wrote down for about 2 weeks, that my humi was steady at 68/66 +-1 ... Which is fine.... I'd say do your tests to ensure your humidor isn't the issue.. if not, I'd be happy with anything in the region of 65-70/65-70 .... After all, the goal is to ensure your cigars are well kept, smokable and flavorful... Not so much to be crazy about obtaining the false perfection of "70/70" ..