Photone – Grow Light Meter: The Most Accurate Light Meter App for Plants

Photone is a free iPhone app developed by Lightray Innovation GmbH that measures photosynthetically active radiation (PAR) as PPFD in µmol/m²/s, calculates the daily light integral (DLI) in mol/m²/d, and measures illuminance in foot-candles or lux. It also allows you to measure light temperature in Kelvin, which helps you determine if a light is suitable for fruiting and flowering or for vegetative growth.

Setting up optimal lighting for your plants can be hard without a proper PAR/PPFD plant light meter. Photone takes the guesswork out of grow lighting by providing industrial-grade accuracy that easily compares to dedicated and expensive quantum PAR sensors. You can learn more about how to achieve maximum accuracy in their white paper. The app also contains useful guiding articles and informative content on their blog.

To access all supported light sources and additional pro features, you can subscribe to Photone Pro. The subscription is auto-renewable and can be managed in Account Settings for your Apple ID. Photone is a proud member of 1% for the Planet and donates at least one percent of all revenue to environmental nonprofit organizations.