That dil flush won’t last anywhere near as long as you think it does. We’ve tried it. It empties a 3liter bottle pretty quicklywith no o2 supply a po2 of 1.2 will take around 13 minutes to drop to .7 - a dil flush that brings it back to 1.2 seems the simplest solution before adding extra bottles or manually adding and cacluating your off board gasses to bring it back up