100% nail on the head, although once I clean out the garage I will have enough room to upgrade to an 8x4 tent.To laserbrn- Most people don't have the ability to just fill their garage or any prt of there house for that matter with lights and plants (Maybe you live in a land without cops, neighbors or family, but we can't all be that lucky.). For whatever reason the size of his set up allows for a 4x4 tent solely dedicated to flowering, not tiny by any means. Since he is confined to this space I'm sure he wants to get the most out of the area he has, in my opinion co2 is always a welcome addition to a well thought out grow. So long as it's done safely and properly it should pay itself off in the long run, though I agree that it may take a bit longer to pay off in this size space. But that is not his question.
Garage in total measures 20x10.