Led Grow Light Guide 2

Question 1

What unit measures the amount of photosynthetically active light reaching a plant's canopy per second per square meter?

Accepted Answer

PPFD (μmol/m²/s)

Answer

Lumens

Answer

Lux

Answer

Kelvin

Question 2

Which light spectrum range primarily drives vegetative leaf growth in plants?

Accepted Answer

Blue (400-500 nm)

Answer

Green (500-600 nm)

Answer

Far-red (700-780 nm)

Answer

Ultraviolet C

Question 3

What does the term 'DLI' stand for in indoor growing?

Accepted Answer

Daily Light Integral

Answer

Direct Lumen Index

Answer

Dynamic Light Intensity

Answer

Diode Light Input

Question 4

Which spectrum is most associated with promoting flowering and fruiting?

Accepted Answer

Red (600-700 nm)

Answer

Blue (450 nm)

Answer

Cyan

Answer

Pure white only

Question 5

What is a key advantage of LED grow lights over HPS lights?

Accepted Answer

Lower heat output and higher energy efficiency

Answer

Higher electricity use

Answer

They emit no usable spectrum

Answer

They cannot be dimmed

Question 6

Hanging an LED grow light too close to seedlings most commonly causes what problem?

Accepted Answer

Light burn and bleaching of leaves

Answer

Excessive stretching

Answer

Root rot

Answer

Nutrient lockout

Question 7

What does 'PPE' (photon efficacy) of an LED fixture describe?

Accepted Answer

μmol of light produced per watt of power

Answer

Total watts consumed

Answer

Color temperature in Kelvin

Answer

Lifespan in hours