hi im running dwc, my bubblers air is sourced outside the room and im pumping 140lt /hr through the stones. Im also running co2 at1200ppm The extraction and inlet fans are turned off during the light cycle, the heat is controlled using a split a/c, Im using a lot of co2, do i need to vent during the dark cycle? If I dont I can totally seal the inlet fan and reduce my co2 consumption. thanks in advance wilson