Sarin, You are putting the cart before the horse here. The condensation will evaporate. The "air pocket" could actually be a good thing for you. I have seen many tanks crack because of a uth that was stuck right to the bottom. I really can't answer any more questions for you until you set up the tank and take readings. I don't know how else to stress this upon you. Nothing else matters but these readings, and you better get them nailed down BEFORE you get your snake or you will have to do it at your snakes expense.