PPFD PAR Meter: Grow Light DLI

LumenLeaf turns your phone into a PPFD and PAR grow light meter for houseplants, grow tents, microgreens, hydroponics, seedlings and planted aquariums. Every feature is free — no ads, no account, no subscription, and it works fully offline.

WHAT YOU CAN MEASURE
• PPFD / PAR in µmol/m²/s
• DLI (Daily Light Integral) in mol/m²/d
• Illuminance in lux or foot-candle
• Colour temperature (CCT) in Kelvin
• Per light source: sunlight, overcast sunlight, white LED 3000K / 4000K / 6500K, HPS, metal halide, CMH / LEC, fluorescent T5 and T8, CFL and halogen

DLI CALCULATOR AND DAILY LIGHT TARGETS
Switch the readout to DLI and LumenLeaf converts your live PPFD into a daily light integral in mol/m²/d, using the photoperiod of the use-case mode you picked — 12, 14, 16 or 18 hours a day. Every plant preset carries its own target PPFD range, target DLI range and photoperiod, so one glance tells you whether the light is on target, too low or too high.

GROW TENT AND GROW LIGHT SETUP
Use-case modes adapt the meter to where you are measuring: grow tent (veg), grow tent (flower), window light, ceiling lamp, microgreens or general use. Map the light spread across your tent, find the hot spots and the dim corners, and set your hanging height with real numbers instead of guesswork.

PAR METER FOR AQUARIUMS AND TERRARIUMS
Aquatic plant presets for Anubias, Java fern and Vallisneria let you use LumenLeaf as a PAR meter for planted aquariums, paludariums and terrariums.

33 PLANT PRESETS WITH TARGET PPFD AND DLI
Monstera, fiddle leaf fig, snake plant, pothos, ZZ plant, spider plant, peace lily, calathea, philodendron, aglaonema, succulents, cacti, echeveria, haworthia, sunflower / radish / pea microgreens, lettuce, tomato and pepper seedlings, strawberry, basil, rosemary, mint, orchids and bromeliads. Add your own plant with a custom PPFD range at any time.

HONEST ABOUT ACCURACY
On most Android phones LumenLeaf reads the ambient light sensor (ALS) and labels the value an estimate. Camera-grade mode switches on only for devices we have actually calibrated, which is a short list today and one we keep extending. The app always shows which mode you are in. An ALS estimate is not a lab-grade reading and we will not pretend otherwise.

When your device runs in camera mode, the built-in guide walks you through building a diffuser from a sheet of ordinary printer paper in about two minutes. There is no hardware to buy.

EVERYTHING IS FREE
✓ All measurements, all light sources, all plant presets
✓ Average, peak and minimum readings
✓ Measurement history with CSV export
✓ No ads, no in-app purchases, no Pro tier
✓ No account and no sign-in
✓ Works completely offline
✓ 23 languages

PRIVACY
LumenLeaf collects zero data. No analytics, no tracking SDKs, no advertising IDs. Your readings never leave your phone.

Made by lapnito.cz s.r.o.