Grow Light CheckTransparent methodology
How Grow Light Check estimates plant-level light
The calculator is a consumer estimation tool, not a laboratory lighting design. It uses physical units, prefers measured evidence, and widens uncertainty when product information is incomplete.
Published and reviewed by Grow Light Check · Updated
Evidence priority
- PPFD measured at a known distance
- Published photosynthetic photon flux (PPF)
- Photon efficacy (PPE) multiplied by actual electrical watts
- Center beam candlepower for a directional reflector
- Lumens converted conservatively for an ordinary broad-white LED
Watts alone are treated as insufficient because they describe power consumption, not photon output or distribution.
Geometry and daily light
Directional lamps use a cosine-power beam derived from the published beam angle. Panels and bars are divided into emitting regions so their size affects near-field distribution. The model calculates PPFD at the leaves and daily light integral as DLI = PPFD × hours × 0.0036 for constant electric lighting.
Transparent covers, mesh and water can reduce output. When selected, bounded transmission estimates are applied after the open-air light calculation.
How a recommendation is chosen
The engine compares simulated PPFD and DLI with practical plant target bands. Uncertainty trials reflect weaker source data and missing specifications. A recommended distance requires most trials to fit; an uncertain fit is labeled accordingly rather than presented as exact.
Known limitations
- CCT does not provide a complete spectral power distribution.
- A beam angle cannot reproduce reflector rings, asymmetric output or every diffuser loss.
- A single center PPFD value does not describe the canopy average.
- Walls and tent reflections are excluded when geometry and reflectance are unknown.
- Watering, temperature, nutrition and species response still affect growth.
For valuable or sensitive setups, confirm the final position with a cosine-corrected PAR or quantum meter.