12/12 Vent and light Problem

I know keeping oyour room dark as possible during the 12 off period. Too do that I'm afraid i would be cutting off the room s fresh air supply when I seal it up at night. I cant vent the room (renting) up until now the dark period wasnt as much of a concern, but I start to flower very soon and I need some ideas how to keep my room dark enough and keep some fresh air coming in. how important is it to keep it itch black?

My room is 5x4x8, IM running a 600w halide soon to be HPS, 7 plants in a closet.

you can get away with not venting in the dark just keep a smallfan running in your room. black black black keep your room dark.

thanks man, so just keep a small fan circulating air during the 12 off? should I run a msall space heater, my night temp is usuallr round 60-63F, (fan might bring it further down)

60Temperature take a look in here....rob

60 is about as low as you want to go my grow has been running 62 at night and 74 in the light. would like 65 and 75

Ya it rarely gets below 65, if so I run the spac heater