It is going to need 2ft of substrate so that he can properly burrow, this will allow him to thermo regulate, and stay hydrated. For substrate, I use dirt/DG/Sand Mixture to create a "sandy loam". Also throw in some wood, leaves, etc.
Read through these...
http://www.savannahmonitor.net/housing/
http://ball-pythons.net/forums/showt...oil-Guide-Tips
http://ball-pythons.net/forums/showt...b-Updates-Tips