I am looking into investing in new setup including this grow tent along with a 1000w HPS, and this fan for exhausting the tent. Being that the system will be enclosed do you think co2 is neccesary or not? I am not exactly informed when it comes to using co2, all i know is that it is expensive, so id like to initially avoid using it if possible.
What I would advise doing is going to your hydro shop and picking up a CO2 test kit. The ones that use the syringe. I think they are like $30 for two tests. This way you can test inside your tent with everything set up and see what kind of ppm's you have. If you have good airflow through the tent and you have it in a room in the house that isn't completely sealed then you should be fine i would imagine. If the ppm's are below 200 then you could try co2 for sure. Also, there are many ways of adding co2 not just with a tank or generator. Look into fermentation.
I wouldnt suggest looking into fermation ... Thats a complete waiste of time, ask anyone. If he said stealth PC then maybe if you had nothing bettter to do... Straight up co2 is expensive. Take your first 5 or 6 steps with getting your gear and getting it dialed before leaping ahead into co2. Co2 is getting allot cheaper then what it use to be, but still do a grow without it, get everything going smooth. If you make it to harvest then spend the cash, get everything the right way with monitor, controller, isolated ventilation, etc. and compare your grow with it to without...
^ What he said. You need to get a couple of grows under your belt with a specific system before adding extra co2 will become truly beneficial for your plants..
If I have the money for it, I always try to add a regulated amount of Co2 into my indoor rooms. So far I have tried giving the plants the co2 during the light, dark, and 24/7. Unfortunatly I haven;'t been able to tell which works best. From my knowledge of plants though, I would recomend to do a steady amount of co2 during your 12 hrs of light.
Gas added to the room during the dark period is wasted. Plants only photosynthesize during the light period. Most controllers have a photosensor that automatically turns the gas off when the lights go out.