LED Grow Light Hanging Height Trades Canopy PPFD Against Coverage Area

… more less Raising an LED spreads its photons over more area, so PPFD at the canopy falls while coverage grows; edges also get less than the centre. Use the maker's PPFD map or a meter: e.g. 400 µmol/m²/s at 30 cm may drop to near 200 at 60 cm.