Recommended PPFDs for Cannabis

Hey, y'all.

I did a quick look around, and I have done some YouTubing, and got some general ideas, but I would like to see if those of us who are using quantum meters and COBs have some input on this, too. Perhaps this thread will be able to help others like me who would like to see if any more experienced growers have some PPFD guidelines they like to use for the different stages of growth. I haven't been able to find any threads where this is really outlined explicitly.
For example, I have heard that around 1000 micromoles per meter squared per second is good amount of energy for plants that are healthy and flowering in optimal conditions. Is this correct? And what kind of numbers should we be shooting for for seedlings and plants in vegetative growth?
I have come to realize that knowing the amount of light that your plants are being exposed to is another variable in the equation that we are using to create healthy, vigorous and productive plants. Having some kind of flux density guidelines might just be very handy to those of us with quantum meters at our disposal.

@OneHitDone recently did a harvest from 242 PPFD, 1.24 GPW if I remember correctly. Good looking nugs.

The upper limit is 1500 but probably best to keep is around 1200 or lower. Some people think the sweet spot is 800-900.

Rahz said:

@OneHitDone recently did a harvest from 242 PPFD, 1.24 GPW if I remember correctly. Good looking nugs.

The upper limit is 1500 but probably best to keep is around 1200 or lower. Some people think the sweet spot is 800-900.

Click to expand...

Generally speaking. Is the 1200-1500 ppfd without additional c02 supplementation?

I would say 700-800 is the most economical without CO² supplementation and temps below 85 °F.

Rayne said:

Generally speaking. Is the 1200-1500 ppfd without additional c02 supplementation?

Click to expand...

The issue going much over 1200 is that if 1200 is the average PPFD you could have hotspots hitting 1500. If your average PPFD is 1500 then hotspots will be over 1500. Even in an ideal situation the yield difference between 1200 and 1500 will be relatively small so I don't see any reason to go much over 1200.

CO2 can be beneficial at any PPFD, especially so at higher levels but can also notably increase yields in the 700s.