I have been itching to build a smoker for a few years now and finally got a hold of a 30 gallon air compressor tank, which will be the cooking chamber. I also have a 30# propane cylinder that I was thinking of using for the firebox. The 30# propane cylinder has a capacity somewhere in the area of 7 gallons. I know that the recommendations call for a firebox that is 30% the size of the cooking chamber which would mean that I need a 9 gallon chamber. I would like to hear peoples opinions on whether or not I should use the propane cylinder for the firebox or not. If I should use it, How should I have it set up, like the location, vertical or horizontal, or any other good tips or tricks? And if I shouldn't, What would be my next best option? Thanks, Daniel J. This is what I am thinking of working with as of now.