This question about lights is probably as old as the first people who started to grow weed with electricity, and has been asked tons of times here too without end in sight. I didn't see a "real dedicated" topic about it either so decided to make one. Maybe some official or unofficial infotopic would be nice, unless it already exists and i'm just unaware. But if there isn't, maybe this topic would be a good start and very useful to especially newer growers like me who owns LED's.
I'm sure there's lots of studies about lights and how much plants (and this case weed) can absorb and use, and how much is too much or too little, and most importantly, what's the optimal amount of light to give your plants. And also i'm sure there's other must know things you have to keep in mind when trying to optimize how much light your plants can use, would love to hear about those too. I'm sure many of you are about min-maxing your setup as much as possible as i am, so i'd like to learn everything about this topic.
And if people would like to share their own setup, including their growing space and light distance/power from seed to harvest, and optionally their own personal experiences for example if someone managed to burn their buds with LED lights.
Lately i was a little bit confused when i saw my buddies 240w QB blasting at full power like 8-9" (20-23cm) from the canopy. I was like wtf, pretty much everyone i've asked and all sites tell to keep your LED's 18-28" (46-71cm) away from the canopy without much other information. He seems to be doing well, i saw his fat buds growing and my own look so thin compared to them. I started growing the same time as him, but i listened to someone's advice and kept my Quantum Boards way too high with little power, so vegging time was pretty long as you can imagine. And i even kept the boards at low power into flower too, after seeing my buddies setup i realized how far behind i am and adjusted my lights much more in hopes to get better results of course.
My setup:
4x4x6.5 (120x120x200cm) tent, a little over 500W total power shared with 4 Quantum Board so 125w per board, and one plant under each board in 5 gallon (19 liter) pots. Managed to train them enough to fill the tent from wall to wall, starting day 40 in flower now. My lights are currently at 14"-16" (35-40cm) away from the tops at about 75-80% power. Temps at day have been lately around 82-84F (28-29c) and humidity 50-53%. It's like 2f (1.5c) hotter at the canopy level, i think that's pretty normal right under the light. I was doing some testing and reading about VPD too, i'm out of the optimal zone because of the high temps/lower humidity that the plants would really want, but that's another topic.
I see in youtube videos people having expensive meters to measure light levels when testing lights, probably would be waste of money to get one of those just for this purpose, unless you know some cheap meter that would work well, and what kind of readings i should be aiming at?
Some of you guys must have perfected the craft and know everything about the topic for sure, what should i do about the lights at the moment? And is there some kind of easy/cheap way to measure the lights on top of charts what are optimal levels in different stages, so i would never have play any guessing games again. That would ease my life so much and i'm not the only one! Also how do you notice if the lights are a little bit too close, what signs should i be looking for?
And of course i'm trying to adjust my temps/humidity at the same time as close to the perfection i can. Even planning to get some extra deep red LED's (and maybe some kind of UV too if the cost/performance is worth it), there's so much studying to do but i've read/seen they really make a difference compared to just plain white Quantum Boards
