Air bubbles in airline for dosing pump

So I have been dosing by hand for a few weeks. I am getting sick of it. I set up an extra aqualifter that I had lying around to dose alk. It drips for about 45 seconds every hour of the night (yes I am aware of the problems with aqualifters and alk). However, air seems to be getting into the airline from the end of the tube that drips, which messes up the flow and it isn;t dosing as much as I planned. I am considering getting a peristaltic pump, but I am not sure if I would have the same issue. I have been cleaning the aqualifter with hot RO/DI water to prevent the alk from clogging the pump. I have done this once, and plan to every week. I have two check valves on the airline. Here is a picture of what my setup is:

Any ideas of how to prevent the air bubbles from getting into the airline? Would this happen with a peristaltic pump as well?

 

I get air in my peristaltic pump hose on the alkalinity side. I think the gas is the result of a reaction in the system since thee is none on the calcium side.

 

Hmm maybe its carbon dioxide? Anybody know how to fix this issue?