Aqau medic quad doser ?? And setup

[Finisher604]

I purchased a quad doser and have figured out the timing schedule,
My issue is I can't seem to get the air bubbles out of the lines to get a consistent amount every time it turns on.

I purchased check valves from King Ed but think they were the wrong ones.
Packing says for air pumps.

Currently I'm looking to dose ALk.

Does anyone else use this doser. I'd love to hear how you use it.