I’m writing a sci-fi novel (or trying) and this is one of my things about living on the moon - you live underground, in rooms sprayed with a non-permiable polymer, with an “air-box” of GMO algae made to control Co2/O2 levels. If the O2 level gets too high, you simply turn the lights down, and vice versa.
It’s then simply to put the oxygen bottles away.
Sounds like a an okay place for an old guy to retire to. Where do I sign up?