Some other things to think about, in the video he is using a 25% blue to red ratio. 1 blue 450 nm light and 3 red 650 nm is obviously 25%. However as I said, red is more efficient or “productive” if you will, and you only need a minimum of 20% 450 nm blue, 1 blue to 4 red would work, then you could arrange the blue in the center of the 4 red in a pattern similar to the number 5 side of a pair of dice, for even distribution of both spectra. Then add groups of 5,000 K to 6,500 K full spectrum LEDs spread evenly among the other groups, which like the higher ‘K’ rated (6500 K and up) florescent lights have a cool blue white light and have extra blue light in its spectra. This way our poor human eyes can see the leaves for their beautiful green color and you add some of the lesser used spectrum for the plant’s use, as well as adding to over all lumens/flux intensity for more robust growth and tweaking up the blue ratio beyond 20%, closer to 25%.
Recent experiments show that providing plants with white LED is also viable because LED color is achieved by using multiple compounds; thus, it is possible to provide all the wavelengths required with a white LED.
Chlorophyll absorption peaks are 430 nm blue and 662 nm red for chlorophyll A, and 453 nm blue and 642 nm red for chlorophyll B. Chlorophyll B is not as abundant as chlorophyll A, and merely help in increasing the absorption range. By having abundant white LEDs, all these spectrum are fully covered as well as making it easier on our human eyes. BTW, I would always recommend wearing polycarbonate “wrap around” safety glasses under HID or high power LED lights. Polycarbonate is naturally 100% UV a/b blocking. The really cheap silver mirrored, ever so slightly gray lenses ones would also reduce glare and make it easier on your eyes