You guys dance all around it without actually hitting the mark. Yes, it's the light, but it's not the intensity (although that matters) and it's not CO2 (although that helps, too). It's the spectrum. Sunlight ranges from UV-b all the way to infrared. Most modern LED grow lights go from blue to red, but not into the further ranges of light spectrum. They do that because UV and IR are not photosynthetically active so the common consensus is they aren't important, plus the diodes are more expensive. However, UV and IR help plants to carry out vital processes, synthesize chemicals, hormones, terpenes and trichomes, and do a bunch of other stuff. UV and IR are extremely important! That's part of the reason outdoor weed is so much more satisfying, and grows so much bigger, than indoor weed. Spectrum, and the fact that outdoor light can get twice as bright as LED light, and its more omnidirectional.
I don't think there's anything I haven't tried over the past decade of growing weed in an attempt to get the best bud possible. I've spent a fortune on different brands of nutes and supplements... I upgraded lights completely four times, did soil, coco, hydro and even aquaponics, but the biggest leap in quality and growth rate and just plain ole goodness came from switching to lights that had UV and IR supplementation bars. My plants started growing twice as fast, were healthier, had better side branching, and the bud ended up more potent and finished flowering about a week sooner.
And all I'm talking about is UV-A. I don't really mess with UV-B. Too much hassle and can be dangerous to you and your plants if overdone. UV-A is plenty enough to make a big difference to your grows.
Ya'll chasing products and tricks when you should be chasing light spectrum. It's cool, tho. I had to learn the hard way, and spend a lot of money before I figured it out. Always thinking there had to be some hack to turn out better bud. Maybe this brand will do it. Maybe this supplement. Am I getting enough calcium? What if the secret is silica? Nope. Just UV and IR. Just get your lights as close as you can to mimicking natural sunlight.
Don't believe me? Try it yourself. Get yourself a UV+IR supplementation bar. You can buy a cheap one on amazon for $50. Sayhon lights have very strong UV+IR, too, and they are budget lights. Won't cost you a fortune. Also, old school HPS and CMH bulbs reach those wavelengths. That's why weed was "so much better back in the day".
