you are correct about the heat. in the summer. on those hot days 90 out side .I would turn the co2 down to 800 ppm hardly turns on. its never lights out around here. the sun is always shining . keep in mind, guys if you can breath in the room the plants can breath as well. unless this guy is not using a co2 controller or its a titan controls piece of shit that jams up keeps adding co2 . I hate titan. made very cheaply trash , and its in a tent the ppm could get to a insane ppm could hurt the plants. only situation I could see with co2 hurting plants.