Zugabe von CO²

As soon as possible. Early co2 in veg will make stems thicker, rootzone bigger and time in veg shorter. As metioned below you need to have 100% control over enviroment. My experience tells me that 80˚F, 60-70% humid and 1200ppm is good when i have my spider farmer sf4000 at 40% power 20" from top. I run co2 tank and solonoid valve, but if you cant afford that you can make your own co2 by adding 2pounds sugar in 1L boiled water, then add 1 gal cold water and about 20g turbo yeast in a container with yeast lock as a beer brewer uses. Lasts for 1,5 weeks in a 3x3 tent. Happy growing!

Also, if you're gonna try it without having the right lights. "A light that hits 1500ppfd in all areas of your tent" you'll need a ppfd/lux meter so you can find the right area in your tent that hits what's needed to match your ppfd/co2 ppm.

When you use co2 it changes the ppfd strenght you give it from the start. So for young plants 4-600ppfd without co2 that is 1-3 even more higher.. so 6-800ppfd and increase that to push it to the 1500ppfd. If you don't have a sealed tent. There's no point. And to use a sealed tent setup you've to be 100% on your PPM of your co2. As the Rh/temp will go sky high into the 30c and 80% rh and beyond very fast. Yes, you can exhaust your tent every 1hr or whatever. But, the point of co2 uses. Is to ensure when in use, you are hitting all the right things. Stuff needed that you jst can't fully do a co2 grow without. Co2 meter, RH/TEMP smart controlled exhaust. Co2 tank, co2 intakes ie values and so on, FYI this stuff, the right gear will set you back 2-500e a piece. GREAT TENT, light that hits 1500ppfd in all areas of your tent. Not jst the middle. So you're gonna need an 800w at min or a special co2 light. And there's very few that use under 700w, most are 1000w lights. And, you need a shit ton of experience pal. You jst can't jump into it. Good Growing

I just started using co2 recently and i swear just one day later i noticed a huge difference. I just happened to buy it late veg but If your gonna use it i would do it all the way start to finish. Why not use every resource available to give your grow that extra edge. Build a big strong structure to hold the dense bud that will come from cranking up co2 and lighting during flower

When your plant can take over 1000 PPFD, usually once they've started flowering. So basically, once your plants can handle having the equivalent of a 450W LED about 18 inches from the canopy. Any increase in CO2 before then is negligible. Then again, any gains from CO2 are relatively negligible in general - IMO it's the absolute last thing in your grow room you should look to invest in, infinitely less important than light, nutrients, water, air flow and environment.