The takeaway is: cannabis can use a ton of light without any negative side effects IF you’ve got the rest of the environment dialed in.
Spectrum doesn’t matter nearly as much as the PPFD the plants are getting.
Definitely worth the watch. Also, check out the other videos on their channel to get some great info on horticulture lighting, UV and far red.
It tapers off though around 1000ppfd
Between 23:00 and 24:00 minuets Dr. Bugbee mentions experiments where they tested up to 1800 PPFD and experienced increased growth rates.
So long as all other factors are in check, more light leads to more growth.
At what point does it bleach? I had a p300 less than a foot and it bleached the tops ppfd would be around 1500
I’ve got some tops bleaching at less than 1000 PPFD. I did make a mistake that had the lights left on for 24h and some of the plants ran into deficiency issues after not getting watered/fed for a day or two of 24h light. Not sure what the cause it.