I am not trying to rush to get any thing just yet, but trying to get more information about the subject to make a better choice. But I am not interested in dyi co2, or compressed tank co2. Trying to buy something that will more or less pay off in the long run and try and do it correct the first time. I am currently building a room thats more or less a 12x9x7. I will end up losing some space after I install 4 inches of foam on all the walls(not losing any height on the ceiling). The room will be fully sealed followed by panda plastic. -My question is do you think I can get by with a 2 burner that is meant for a 10x10 or should I get the 4 burner? -Any one using/used the water cooled Co2 Generators? Thoughts on it? I was looking at the HydroGen water cooled unit(briefly). I seen that it can go on a recirculate system. I thought about if I had a 55 gallon drum burried in the ground so the ground kept it cool, if this would be enough to keep the Co2 Generator cooled. I am not sure how fast it would heat up the water as it was exchanging it and if the ground could keep up with it. -Any one using tankless water heater for the co2? -What unit are you using and how has it worked out for you?