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How to Measure and Record PPFD in GrowScope

PPFD (photosynthetic photon flux density) tells you how much usable light is hitting a specific point right now. GrowScope does not use the phone camera as a PPFD meter. Instead, you measure PPFD using a compatible PPFD/light meter and enter the measured value into GrowScope.

How to do this in GrowScope

  1. Open Light.
  2. Select the plant.
  3. Open the PPFD measurement form.
  4. Measure PPFD at the required position under the grow light, using a compatible PPFD meter (GrowScope includes a built-in step-by-step guide for using the free Photone app with its own camera-based method — that measurement happens inside Photone, not GrowScope).
  5. Enter the measured PPFD value (1–3000 µmol/m²/s).
  6. Select the light hours (photoperiod) and the measurement source — Photone, or another device / manual.
  7. Save the reading.

PPFD Tracking

Category
Lighting
Purpose
Record a PPFD measurement for a plant, taken with an external meter.
Input
PPFD value (measured externally, typed in manually)
Unit
µmol/m²/s
Location
Light → PPFD measurement form (per plant)
User action
  1. Select the plant
  2. Measure PPFD with a compatible external meter
  3. Enter the PPFD value, light hours, and measurement source
  4. Save the reading
Output
The reading is saved to the plant's light history with a confirmation message, calibrates the 3D light map, and is prompted for on a weekly cadence as part of the Today screen's checklist.
Used by
3D Light Map calibration, DLI calculation, CO2 enrichment target, AI equipment-placement optimizer, Adaptive watering AI context
Related
How DLI Works in GrowScope, 3D Light Map and Equipment Placement, CO2 Enrichment Targets

Notes

  • GrowScope has no in-app camera-based light meter. The only camera use in the lighting feature is Photone's own external measurement method, which the app links out to via a built-in guide — the number still has to be typed into GrowScope by hand.
  • There are three other places a PPFD number can be entered besides the main form above: a one-time dimmer-calibration screen (pairs a dimmer % with a PPFD reading at that setting), a tap-to-add calibration point directly on the 3D light map, and the same PPFD step surfaced inside the weekly guided "Today" plant flow — all of them feed the same underlying light model.
  • It's true that no phone-based method — Photone's or any other app's — continuously measures PPFD the way a permanently mounted quantum sensor does; every reading is a spot measurement at the moment it's taken. GrowScope's response to that gap is the 3D light map (see Lighting documentation): each spot PPFD reading calibrates a physically modeled light field for the whole space, so the map can estimate coverage, dark zones, and hotspots at points and times you didn't measure, instead of only knowing the single spot and moment you last checked.

Frequently asked questions

Does GrowScope estimate PPFD from my phone's camera?

No. GrowScope does not use the phone camera as a PPFD meter. You measure PPFD with a compatible PPFD/light meter and enter the measured value into GrowScope.

What if I don't have a dedicated PPFD meter?

GrowScope includes a built-in guide for using the free Photone app, which uses your phone's front camera as a light sensor — but that measurement happens inside Photone; GrowScope only accepts the resulting number as manual input.