Light Map & Steering Tool

Size your lights and check PPFD and DLI against your stage targets. Then use spectrum, not just intensity: red:far-red, blue fraction, and crop-steering guidance to shape how the crop grows.

About this tool: PPFD, DLI, and choosing a light

🦬 BizonTip!

Feed this the fixture's real PPF from its PPFD map, not a headline "equivalent watts" number, and if you can, verify with a quantum meter at the canopy in several spots: bench edges routinely read half the center. Remember DLI, not instantaneous PPFD, is what grows the plant: if you can't reach the intensity you want, a longer photoperiod often gets you the same DLI (except on photoperiod-sensitive crops). Re-check as the canopy rises toward the light.

Coverage & Photoperiod

How do you want to set your own target?

Area length ft

Area width ft

Growing environment

Photoperiod hours of light / day

Target stage

Custom DLI target

optional, mol/m²/d, overrides the stage band

Primary Fixtures

How is fixture output specified?

Number of fixtures

PPF per fixture µmol/s (from the spec sheet), not watts. For watts, switch to Watts × efficacy above.

Fixture size (W × L)

the lit footprint of one fixture

Beam angle wider spreads light, narrows the hot spot

Spectrum of these lights

Rough split from the spec sheet or channel settings; drives red:far-red, blue fraction, steering guidance, and the light map's tint. Percentages don't need to add to 100. Supplemental fixtures (far red, veg, bloom) are added on the light map with their own spectra, and Results blends them in by photon share.

Blue % · 400–500 nm

Green % · 500–600 nm

Red % · 600–700 nm

Far-red % · 700–800 nm

Light map

Distance to canopy ft from fixture face to canopy top

Fixture spacing

ft between centers, updates as you type; blank = spread evenly

Add a fixture

A modeled map, not a measurement. These numbers come from the mathematics of your fixture specs (area sources with the beam you chose), lifted by the reflections your growing environment sends back. That lift is spread evenly over the map, but real bounced light favors the dim edges over the bright middle, so your corners are likely a little better than drawn, never worse. Treat it as a planning map, then verify with a quantum meter at the canopy.

Results

Average PPFD assumes even coverage and no losses, so it reads high. Real canopy PPFD drops toward the edges.

Crop steering

What do you want the light to do?

Guidance grounded in photobiology (phytochrome, cryptochrome, UV photoreceptors), tagged by how well established it is. Crop-specific magnitudes vary, so treat it as a starting recipe and verify for your crop.

Keeps this as the lighting for the space you're on. To keep it as a named setup you can load onto any space, save it as a recipe below.

Lighting Recipes

Save current setup as a recipe

Recipe name

A recipe keeps the whole page: room and environment, photoperiod, targets, fixtures and their spectrum, and your light map layout. Load it on any space to put that setup back.

Load a recipe

No saved recipes yet.

About this tool: PPFD, DLI, and choosing a light

"Lux" doesn't measure what you need to measure to understand plant growth.

Lux meters measure what the human eye sees; photosynthesis utilizes photons from 400 to 700 nm, which is called PPFD. No direct conversion exists between the two.

DLI is the accumulation of PPFD over time. (photons per square meter per day)

PPFD is a rate. Plants respond to the daily total. (photons per square meter per second)

DLI = PPFD × hours × 0.0036

Crop and stage	Target DLI
Seedlings and cuttings	6 to 12
Lettuce and leafy greens	12 to 17
Herbs	16 to 25
Tomatoes, peppers, cucumbers	25 to 35
Cannabis	30 to 40

Measure at the canopy

Canopy top, center and corners. Bench edges will be lower than the center.

More light stops helping, then hurts

An abundance of photons saturates, but can also also overwhelm. There is such thing as too much light.

Spectrum

Blue compacts growth, red is most efficient per watt, far-red stretches, green penetrates deepest. Total light complex matters more than colour.

Compare fixtures on efficacy

Compare µmol/J, not watts. Current LEDs generally run 2.5 to 3.4.

Light Map & Steering Tool