I have a Liberty gun safe and it came with a dehumidifier that I plug in every so often to recharge. It has all kinds of settings and tells humidity level and temperature. If humidity gets bad it beeps..Then I just plug it in to recharge. I been keeping cues inside for 10 years now without any issues.. I also heard a guy say he kept a box of bakeing soda in his safe. LOL Dont know if its enough but he said he has no problems. << ED