Wow seriously? 20 gallons for an adult ball python? Wow, I guess I have much to learn.
Isn't that too small for an adult BP thoguh? I know they aren't active snakes, but shouldn't it get more space to stretch out? I was planning to get a 40 eventually when my bp grows. I guess 30 is better?
Anyway, sorry to derail. My opinion is 30 or 40 for an adult.