Plant Light Meter: Lux & DLI

Plant Light Meter answers the question every plant owner asks at a window: is it bright enough here for this plant? Lay the phone where the plant stands, screen facing the light, and the sun climbs the dial to the reading. The dial is marked in the bands care labels use, from too dark to direct sun, and the number is in lux. Choose the plant from a library of common houseplants, from snake plant to fiddle-leaf fig to basil, and the dial shows the range it is comfortable in. The verdict is one line: enough light here, too dark for it, or too bright and the leaves may scorch. No plant chosen? The app lists the plants that would be happy in this light. Looking for the brightest place in the room? Start the scan, carry the phone around, and a rising note marks each brighter spot found; the best reading stays on screen. Keep the spots that matter. Every saved place sits on a shelf, brightest first, with the plant that lives there and whether it is happy. Read a spot morning, noon and evening and its page draws the day as a curve and works out the daily light, DLI, the way grow guides count it, rather than guessing from one reading and a number of hours. Under a grow light, switch the meter to the lamp's spectrum for PPFD and DLI, and see how far the lamp should hang for seedlings, leafy plants, herbs or fruiting plants, from the reading at the leaves. A phone camera is not a laboratory meter. The reading is an estimate, good to within a light band, and if you own a lux meter you can calibrate the app against it in a few seconds. The camera only reads its exposure: no photo is taken, stored or sent. No sign-up, no connection required, and nothing about you is gathered. Free: the meter, the bands, the plant verdict and the room scan. Plant Light Pro, paid once, adds the shelf of spots, the day curve with daily light, and grow-light mode. It never renews.