I can't stop thinking about potential sources, I wonder if my in-laws would mind being tubed up to the tank? ;-)
I had never seen that article before, very interesting. Makes me think of all that CO2 that is in the blow-up mattress in my living room, it took me an hour to fill that thing up! Are there any substances we release while breathing that could pose any problems? Does CO2 in the bag remain unchanged over time? (another words, if I were to deflate my mattress after a week or so, would the CO2 and other elements be the same as the first day?
-- Paul Krombholz in sunny, cool, central Mississippi