Take a look at this YouTube from Boveda. They discuss humidity control with the guy who runs their lab.I am surprised that new boxes of cigars could pull your RH that low. If the boxes were that dried out, I'd be worried that the cigars in those boxes had been completely dried out too. I try to keep my cc and nc at around 65% and around 63 F. IIRC the recommendation that comes with CC is to keep the temp between 16C-18C and 65%-70% RH, though 70% seems kind of high.