Great run down Hoppy.... you seem like a really sharp cat

You should add this to the APC review archive
I THINK in my very limited knowledge of chemistry that once that equilibrium is reached that the levels would all equal out (though maybe to some degree of variance) ... even the air portion of the Drop Tester would reach equilibrium with the CO2 levels in the tank. If CO2 and O2 were NOT independant of each other is were I would think the big problems would come into play.... *shrug*
-Justin
One Mynds Eye