sorry to hear this; that's why the atmospheric controllers automatically shut the fans off when CO2 is engaged. Also, for $40 you could get a lot of sugar and yeast to do the same thing...well, it arrived today and something occurred to me as I was hanging it in the tent.... My exhaust fan is going to suck any CO2 that the bag might provide out of there LONG before the plant has a chance to absorb any of it...lol!!!! oh well..... live and learn I guess