Leaves are slightly translucent, the light will pass through the entire leaf and interact with all chloroplasts; the chloroplasts that allow for photosynthesis are held in the middle of the leaf between the upper and lower epidermis, the underside of leaves can photosynthesize. Just because they do it at a rate far lower because of nature than the top of the leaves is meaningless when it comes to the studies of under canopy lighting. So top lighting 1000 watt HPS = 100% of photosynthesis and the under canopy lighting with weak LEDS can add an additional 5 - 10% yield and growth why knock it? Why the beef? Not to mention as I posted the early 80s studies of blue light under the canopy and stomatal opening... So 85+ degrees + 1600 ppm Co2 + passive blue light under canopy can lead to explosive growth and has been shown in University studies. It's like you're either a bunch of old 1969 dead head Woodstock hippies that are set in your ways or a bunch of young guns that aren't capable of reading a .gov peer reviewed article from a University. I won't bring it up again, do your thing... Have a nice day..
