I know I am bumping an old thread, but I have a question about how this works.
I bought the check valve kallmond linked to. My question is how to install it. When I suck on the valve, I can only get air movement on one end. So I assume this is going to be the open end, to which the air line gets attached. My question is, how do you prevent water from getting through. It seems to me that there is nothing stopping the flow. Should the airline be closed off somehow? What about running the airline tubing back into the tank?