Quote Originally Posted by MrLang View Post
A lot of long replies so I apologize if I'm repeating someone:

73 - 78 is perfectly fine for ambient temps. Don't run a heat lamp - it's not necessary. Not running a heat lamp means you won't fry your humidity, so the question of substrate becomes less important.
Not trying to nitpick, but since when is 73 at all ok for a ball python? I'll admit I've only really been keeping them for a couple years now but I've always understood the minimum ambients to be 80°. I'm sure it'd be fine with an occasional dip to 78, but I would've thought that any significant time at 73 would result in an RI of some sort.