I am not sure. At 40 degree latitude, peak summer sun is about xxxxx. But the sun is much stronger at the equator than it is in our more northerly latitudes and marijuana grows there very well. Under normal conditions growers keep their lights about 18 inches from the tops of the canopy. The peak light under these lights at that distance is about 4500 foot-candles.
Using water-cooled lights, which remove most of the heat associated with lights, gardeners place the plants 9-12 inches from the light. This more than doubles the intensity.
I think you can bring the light intensity to 12,000 foot-candles without a problem.
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