DIY CO2 reactor problem

I have recently made a DIY reactor for the first time and my plants are a lot better than before. The reactor is made of a pump and reactor chamber with filter pad at the end. This was originally put vertically in my aquarium but the gas would accumulate at the top of the reactor chamber. I did a few adjustments and now the reactor is placed vertically in the aquarium. So far, the gas is still accumulating and seems to not be dissolving. I have disconnected all the airlines and waited for the pump to dissolve the gas but even after hourse, the gas has not dissolved. I'm looking for alternative designs as this reactor takes up most of my space in my 20 gal. I'm thinking that maybe its not dissolving because the gas saturation level at the top of the aquarium is too high and the gas won't easily dissolve there. I can't put this reactor in the bottom because it takes up space and blocks light. What is the reason that my gas isn't dissolving? Also, there is virtually no turbulence on the water surface of my tank and the gas that is trapped in my reactor chamber is heavily agitated, and it still does not dissolve.


Thanks for any help!