To add to what bsash already stated, Make sure you cover the lid to the tank (I'm assuming it is screen) with foil as it will help greatly with keeping the humidity levels where you want them. You will also want to cover three sides of the tank with a dark construction paper or some other covering to give the snake more security. Our 800+ Gram male is currently in a 20 gallon long tank and we feed him in said tank. He eats one small rat every 7 days unless he goes off feed (which he did for 3 months this past winter). I also use shredded aspen as bedding.