Don't forget like I did to set up your room so that your light is ventilated separatly from and to outside your grow area. You will also need to have all ventalation turned off while the co2 is on. This is a big concern when designing your setup.

I thought I would just add co2 later when I could afford it, not researching it first. If you don't want co2 to be a complete waste of time and money the lights need to be on and ventilation needs to be off when co2 is on. I really wish someone would have told me this a few years ago. Now I want to add it, but I have to tear my setup completely apart, including the wall behind the grow area.

good luck.