aquarium size

Hi, I am going to a Reptile Expo in St.Louis on August 24 to get my first corn. I still have to get the aquarium though. I have heard that the ideal size is about a 20 or 30 gallon tank. I already have two ten gallon aquariums so I wouldn't have to go out and buy a new aquarium right away. If I use the ten gallon then I am going to have to buy a cage lid anyway so I figured I would invest and buy a 20 gallon right off the bat and the 20 gallon size cage lid so I might save myself some money in the long run. Any input is appreciated.

Get the twenty gallon. There are twenty gallon long and twenty gallon high versions. Get the long one. Good luck!