So last fall timing was good to combine my garden cabinet (3x3x5) and production of the co2 byproduct for seasonal wine making. Mid to Late September is when the grapes and juice arrive from California this was late veg, early flower time for my cabinet so I figured I'd just take some tubing to vent the primary ferment to it. So to be clear my cabinet is in a quasi temperature controlled (not warm in the winter and not cool in the summer) garage about 25 x 30, sometimes my wife gets to park her car there, but not very often. I run a small vent fan in the summer for exhaust but it wasn't needed at this time so I only had a small amount of air change. I was able to test the levels using a colormetric tube to be 1000 ppm inside the cabinet at the end when I had 2 (two) 6 gallon carboys reaching the end. I made ~24 gallons of first run wine, then to extend the fun I did a second run on both the grape batches by adding juice/sugar to the spent must and refermenting another 12 gallons of some, well Ill call it a homemade maddog 20/20. Continued through to late flower by throwing in all the sugars in the pantry that expired in 2002, agave, corn syrup, corn meal (expired 1999??), some grains random bulk foods isle grains from who knows when, then it all got dumped on the compost pile. Never used CO2 before but growth was much more vigorous. This time I am not so lucky for the timing but I'm curious to see how far 20lbs of sugar will go, and since the 12 gallons of second run is probably crap I might make a kit or wine from condensed juice if I can get a reasonable price on some. Also I am going to try to make something simple to divert and store the CO2 during lights off. What you see here is a mortise and tenon construction european beechwood 3x3x5 cabinet with 1/4 vinyl coated masonite for 2 of the walls and the front sliding door, the other wall is open and against concrete, and a micro porous automatic venting canvas roof. The light is 620 watts max of CXB3070 and 3590, 185 watts T5, and a 2ft pure uv. The UV runs intermittent, and 440 of the led watts run 10 of 17 veg hours. The 200w roledro is currently not in the lighting scheme. I've got a few experiments in mind for this run, maybe @ttystikk will help me with a heat recovery system?