Ric, in my opinion you have hit a home run, saying how important air movement is. Fungi and algae don't like moving air, they love stagnant air. It is amazing how many of those with greenhouses don't have any or at least very little air movement. And they wonder why their tropical plants rot, why algae and mildew form so quickly, and why insects are an almost constant problem. Come on guys, a box fan costs pennies a day to run.