Question 1

What is Daily Light Integral (DLI) and why is PPFD alone not enough?

Accepted Answer

PPFD measures instantaneous light intensity (µmol/m²/s), whereas DLI measures cumulative daily photon volume (mol/m²/day). Formula: DLI = PPFD × Hours × 0.0036.

Question 2

Can you give plants 24 hours of light to hit target DLI faster?

Accepted Answer

Day-neutral crops like autoflowers and microgreens tolerate 24/0 light, but photoperiodic plants require a dark cycle to flower and translocate carbohydrates.

Grow Light DLI Calculator

Calculate DLI: Input canopy PPFD (µmol/m²/s) + Photoperiod hours → Output DLI in mol/m²/day
Find Required PPFD: Input target crop DLI + Photoperiod hours → Output minimum required fixture PPFD
Find Photoperiod Hours: Input target crop DLI + Current lamp PPFD → Output required timer ON duration

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