PPFD for cannabis: seedlings 200–400, vegetative 400–600, flowering 600–1000+ μmol/m²/s — photosynthetic photon flux and daily light integral applied correctly.
PPFD measures usable photons per square metre and second (μmol/m²/s). Cannabis requires: Seedlings 200-400, Vegetative 400-600, Flowering 600-1000+ PPFD. Calculation: Light intensity × area × efficiency. DLI (Daily Light Integral) = PPFD × photoperiod × 0.0036. Optimal DLI: Vegetative 30-40, flowering 40-60 mol/m²/day.
PPFD stands for photosynthetic photon flux density and measures the amount of light that plants receive in a given area. It is important because it affects photosynthesis and, consequently, the growth and yield of cannabis.
To calculate the PPFD, you need the light intensity of the lamp in μmol/s and the area it covers. Divide the light intensity by the area in m² to get the PPFD in μmol/m²/s.
For seedlings, 200–400 μmol/m²/s is ideal, while the vegetative phase requires 400–600 μmol/m²/s. During the flowering phase, the PPFD should be between 600 and 1000 μmol/m²/s.
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