Find your Daily Light Integral and dial in the perfect light intensity for every growth stage.
You can estimate PPFD from lux readings using a free phone app (like "Lux Light Meter"). The conversion depends on your light type:
| Stage | DLI Target | PPFD @ 18h | PPFD @ 12h |
|---|---|---|---|
| 🌱 Clone / Seedling | 12–20 | 185–310 | 278–463 |
| 🌿 Vegetative | 25–40 | 386–617 | 579–926 |
| 🌸 Flowering | 38–55 | 586–849 | 880–1,273 |
| 🔥 Max (w/ CO₂) | 55–65 | 849–1,003 | 1,273–1,505 |
More light ≠ always better. Without supplemental CO₂, cannabis maxes out around 800–900 PPFD. Going higher just wastes electricity and stresses plants. With CO₂ at 1200+ ppm, you can push to 1200–1500 PPFD effectively.
Light distance matters. PPFD drops dramatically with distance — moving a light 6 inches further can reduce intensity 20–30%. Always measure at canopy level, not at the light.
DLI = PPFD × (hours × 3600) ÷ 1,000,000