This is my kind of thread.
Gavita says " for medical cannabis there is a near linear increase in yield up to about 1100umols." I personally believe that 1300umols is just dandy. But with a co2 boost I can see them taking on 1500+ with no problem.
One thing ing I think is key for LEDs specificaly(not induction)is the distance from the canopy that the measurements are taken. The light needs time to blend and unify. The closeness is what I feel does the bleaching...my theory is same intensity from 2x farther away would never have bleached. Technically farther but same intensity more intense, but they plants like the distance from what I have seen.
As for the a51 sites info, I mean this with all do respects...I don't think it is wrong, but it doesn't tell the whole story.
The 800umol peak comes from the old standard of 700umols being the ideal for high light intensity crops...vegetables, not cannabis specifically...which we know from outdoors and indoors can take and do well with plenty more.
He is making it seem that the 800umols is the saturation level, but it actually closer(still low) to the point of diminishing returns(PODR). But point of dismissing returns doesn't mean no increases after it...just that you will not get as much out of the same input...but there is still a gain in yield and other things after the PODR. The saturation level is the point at which the plant literally can't photosynthesize any more... Saturation point is still up for debate(as is PODR)but good sources and my self, think 1700ish. But let's not forget the sun at 2000umols. Handling higher intensity seems much easier for plants when the souce is far away(1000hps are hung higher, and the sun is way up there) like I mention before about the bleaching. The edge numbers I think he may have come up with on his own. And they may be true and tested in house, but 1000w hps are closer to 400umols(350-400) very outer edge of 4x4, so makes me wonder. I want my out plants to be as close to the lower end of ideal(700umols) as possible...I think that even 600umols if it was across every inch of canopy would be great. But I also think that 1000umols across the whole thing would be better.
I have been been vegging under 1000center-600outer and the plants are loving it...fast growth but also thick, strong, and healthy too(get your minds out of the gutter) . Which to me shows they respond great and are ready to support big buds.
Hyroot...I ran my IG and pontoons at 12" and they never had any signs of bleaching/burn. Chaz warned my so I kept an eye out, but they we're fine and loving it.
EDIT:
I just want to make it clear that is still think a51 has the best and truest site of anyone. He knows what things really show performance capabilities and has great info for the new comers that don't know what to really look at yet. There is nothing wrong on their site. I just have my own views on certain things.
