is the air in the co2 reactor at the end of the day cycle (after the co2 has been shut off) just air, or is it still co2? Running many bubbles per second all day leads to some air at top of the reactor at the end of the day. I'm pretty sure its 95% air but does anyone now for sure? My reactor has a out gas button to purge pressure at the top of it, and i usually expel the gas cause i assume it's just air. Am I wrong?