ok if the co2 bubbles collect at the input end, they would continue to build up and grow to the point that they would interfere with the water flow, and at that point begin to travel along with the water flow? So one could have a build up of bubbles, but only to a point. just trying to think this out in a logical way?
Yes, I agree with that. The problem would be that the big bubble of CO2 didn't get dissolved into the water so the efficiency of the reactor would suffer. My external reactor, vertical, also built up a big bubble at the top, and it worked fine for me, but I knew it could be more efficient if the bubble didn't build up.
Breaking bread, I also enjoy working with the equipment as much as the rest of the hobby too. (I would say I enjoy it more, but I know I'm supposed to enjoy the plants and fish the most.