I've been doing CO2 infrequently for a little bit, but haven't fully committed because I haven't found an easy way to do it. I started out with normal bag breathing which was pretty annoying. Then, I moved to Haidut's method of the gallon jug with the hole in the bottom. That was also annoying to do because of how much time it required. So, I landed upon the image above where you cut off the bottom of a bottle and tape a bag securely to the end. This way the CO2 stays trapped in the bottle, its easy to do, and you don't have to store a big jug upside down. The only problem is the fact that moisture will build up in the bottle. Any suggestions on how to improve this?