CO2 During Lights Out?

Is it ok to leave CO2 in the room during lights out? Im about to start the flowering stage and I want to know if I should leave my home made
CO2 in the room with them during the day and night?

It is ok, but a waste of Co2.The plants won't use much of it when the lights are off.

you can leave it in with your plants. it won't do much in the dark, but it beats moving it (them?) every day