Stagnant air is poor quality and will need to be cycled intermittently throughout the day in order ot bring in fresh air to our plants. A lack of CO2 or oxygen in a sealed climate will cause issues ranging from poor transpiration rates to mold spore build ups within the microclimate. This older stagnant air needs to be replaced with fresh air, and that's where inline fans come in. A built in exhaust fan (high side) and inflow fan (low side) will help your cultivars thrive. Keep things moving, keep things fresh, use inlines and all will fall into place.