Get rid of the 55. You will never keep the heat and humidity levels where you want them. If you insist on using such a big enclosure then close the top off with just leaving a small gap on one end for ventilation. Another thing you can do is get a plastic milk jug cut the top off of it and fill it with vermiculite and water just like you would do a mix for incubating eggs. Put the container in the cage and keep it moist. When misting do so with warm water. It will help spike the humidity. The vermiculite mixture will stay moist and help promote humidity. But again a cage that big for one ball python does have alot of useless space