I believe plants dont use Co2 at night. It is only beneficial when a lot of light is being used and temperatures are high. That's what I read somewhere anyway in more that one piece of literature - but I could be wrong. Any one know difinitively.

TGT
Tom Green Thumb Reviewed by Tom Green Thumb on . Fans On or Off during Lights Out?? I have not been running my fans during "lights out" and I am growing in a closet where the only airflow is provided by fans. The only air that comes in is through the duct work during that time. Is this ok? I'm not like suffocating my plants for 6 hours or anything right?? I'm trying to figure out what happened to my seedlings and just trying cover all the bases. Rating: 5