I just posted the other day that I have a small tank that was used for propelling beer and soda thru a fountain/tap at a bar. The tank contains NOS and CO2. I'm not sure of the ppm of either one but this is another possible place to find CO2. And you would probably have a much easier time finding/refiling a tank if it was beer gas. Also... I'm an avid paintballer and the marker I play with uses small 20 oz tanks of pure co2 which can be refilled at the local hobby shop for like $0.30 a pop. Gathering a number of these tanks and using a small regulator could also be a solution. Let me knowwhat you think
__________________ Good Luck, and Good Farming!  JayBlunts |