Hello all I was looking to purchase my first snake.I was looking a bulls because they corns and kings are too small for my liking and BP aren't(from what I've heard and read)good feeders.So I started looking up on Bulls.I do know as babies they are hissy and they have a temper that will calm with years of handling.So I figure Bulls look good and aren't bad feeders and get big but not enormus.But there seems to be a lack of information and care sheets,but from what I have read they have very simlar requirements to Kings and corns since they are North American snakes.But I still have a few questions I would like to be answered.

-The place I planned on purchasing from have CB 09 Yearlings.Can someone explain this too me please.
-From the caresheets I have read I don't really see a real humidity answer.I've seen from 30-40% to 50-60%. Rough Idea anyone?
-I know eventually I will have to place a bull in a bigger tank,but how long should would one grow out of a 30x12.5x12.5 tank?