So, I have been looking at ways to increase CO2 in my grow room on the cheap. After looking at natural gas and propane generators I decided to buy a small oil lamp and see what kind of CO2 it would generate. The lamp was super small and cheap, I paid $3 for it at a local store. When I fired it up my CO2 was at 433, the first picture is about 5 minutes later, I couldn't believe it was increasing that quick and ran upstairs to grab my camera. After 33 minutes my CO2 was at 800. The room size is 10x10x10 so 1000 cubic feet total, it increased by ~400ppm after 33 minutes. It pretty much stabled out and bounced back and forth between 750 and 800 for another two hours when I turned it off. I will be investing in a larger lamp for further testing but as you can see, a very small flame will increase the PPM quite a bit in an enclosed room. I don't know how comfortable I would be with it in a tent but this room has concrete floors and blocks up 2' high so I am not much worried about it in there. I will update after I get a larger lamp.