Led Grow Light Key Features 4

Question 1

The Daily Light Integral (DLI) represents what?

Accepted Answer

Total moles of PAR light delivered per square meter per day

Answer

DLI sums PPFD over the photoperiod, expressed as mol/m²/day, guiding total daily light dosing.

Question 2

If a fixture has high PPF but a wide beam angle, what is the likely effect on PPFD?

Accepted Answer

Lower PPFD at any single point due to spread

Answer

Spreading the same photons over a larger area reduces intensity at each point.

Question 3

Raising a grow light farther from the canopy generally does what?

Accepted Answer

Decreases PPFD but widens coverage

Answer

Light follows the inverse-square law, so greater distance lowers intensity while expanding the footprint.

Question 4

Why is photon efficacy (μmol/J) a better comparison metric than wattage alone?

Accepted Answer

It accounts for usable light produced per energy unit

Answer

Efficacy normalizes light output against power use, letting you compare true performance regardless of wattage.

Question 5

Which spectrum bias is typically emphasized during the seedling/vegetative stage?

Accepted Answer

More blue light to encourage compact, leafy growth

Answer

Blue-rich light promotes shorter internodes and bushy vegetative development.

Led Grow Practice Test