Parts per million OF WHAT?
another idea is using the chemical process of electrolysis using IRON and GOLD, The Oxygen will be sent to the atmosphere and the HYGN will be sent to a temperature stabilizer using HYGN, sensors n stuff.
+1 and fav, very cozy looking, ground acts like ground (layered, harder layers on bottom, maybe add some deco to it but doesn't matter either way), compact factory