I have a Grozone Co2 controller. I just have week old baby seedlings in my tent right now under some CFL's. The reading I'm getting is around 700-720 PPM. I was stunned. I was thinking maybe its just me being there that's making it high. So I exited my tent, opened the windows, let some draft in, came back in and it was still around 700. I took the controller to my window to see what I was getting from the outside air and it was around 520 PPM. Sure enough, I put it back into my tent and it goes back up to 700. Not that I'm complaining, but just curious as to why my Co2 PPM levels are so high in the tent, even when the tent is open and the closet door is open too. Any thoughts?