I just went through the tank size dilemma myself and settled on a 40 gallon breeder tank. My corn is only about 16" right now, but I couldn't pass on this deal and it wasn't gonna be around long. I was gonna go with a 20 long, but I'm one to spend lots of time decorating the tank to make it "perfect", to me at least. I was just imagining how much I can do with the deco in a 40 gallon. It's already been said, but as long as the temps are good and you provide lots of hides, the bigger the tank, the better IMO. Of course, it's also easy for me to say that, as I've only got the one snake(for now), so I can indulge a lil' more for this guy...