To figure out the optimal distance the led panel should be from the canopy, I think this makes sense. Most led panels have 4 to 11 spectrum's of light. Its my belief that your plant will grow best when it receives all these bands simultaneously. Also light degrades with distance so you will want to keep the light as close as possible. So basically, you want to keep the light as close as possible while blending all the bands of light. So we want to take the distance from the furthest apart leds and find out the distance in which they blend To do this we need to use a little math. I never took trigonometry so please correct me if my math is wrong. So with this I can see that my led panel will blend all its bands of light at about 9.5". Therefore keeping my light at 9.5" above the canopy is optimal. Please chime in with your input and let me know what you think about my theory.