Thanks for all the help regarding my earlier post in which I asked: >So my question is: is there an equally cheap alternative to yeast for producing CO2? I received a lot of offers for help re: putting together a reasonably priced pressure tank + regulator system. I am afraid I misled you a little. I already am using such a system on one of my tanks. The purpose of my post, however, was to find true *alternatives* to bottle and yeast.