Originally Posted by scoupland
Steve001--I looked at the thread you noted and see that you put together an array of lights that allowed you to achieve a very high CRI. How much do the particular colors of the lights matter? For example, you don't have a far red light in your array. How do you know which of the colors the plants most utilize? My question is whether CRI is the bottom line, and how much does your choice of colors matter?
In my opinion having a wide gamut of different led colors and in the right ratios emulates natural looking light at noon in the tropics and most temperate regions. Note most of the plants we grow are tropical along with a few temperate plants. The photos of tanks I've seen for the last 27 years all try to emulate noon sunlight to varying success.
Which wavelengths of sunlight plants use can be easily found on the web.
I would have put the deep red [720nm] in there but the design app only allows 15 leds. There is a small photosynthetic peak at that wavelength.
CRI isn't the bottom line, but very high CRI along [ visually pleasing to look at tank ] with a Kelvin temp around 5500-5900 and good PAR output, are I feel, the best combination. So with this technology available that allows one to do just that why not use it if your budget allows?