I'm trying to understand. Are you referring to the tubing running from the regulator to the bubble counter or from the bubble counter to the pump? And what exactly do you mean by air gaps? If you are saying that there is liquid in your CO2 tubing and that there are air gaps between the liquid, then there is generally, something wrong. You should have no liquid in your gas tubing at all. I am not familiar with a CalRx reactor so I may be wrong there. If there is liquid in your gas tubing between the regulator and the bubble counter this is no good. You should have a check valve between the bubble counter and your regulator at all times. Liquid getting into your regulator is certain death for the regulator.