Photone - Grow Light Meter 4+

Take the guesswork out of grow lighting! Measure PAR / PPFD, lux, fc, and kelvin: All within the most accurate light meter app out there.

Setting up your plants' optimal lighting is not easy, if not impossible without a proper PAR / PPFD plant light meter. Calculating your indoor garden's daily light integral (DLI) to match your plants' needs allows you to optimize your lighting for maximal yield at minimal electricity consumption.

Our Photone grow light meter app 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 can help you determine if a light is suitable for fruiting and flowering or for vegetative growth.

Photone is by far the most accurate light meter app for plants and achieves industrial grade accuracy that easily compares to dedicated and very expensive quantum PAR sensors. You can learn more on how we achieve ±5% accuracy compared to research grade laboratory equipment and how to achieve maximum accuracy by yourself in our white paper: https://growlightmeter.com/whitepaper/

The Photone app also contains useful guiding articles to help you get the most out of your plant lighting. In addition, you can find more informative and educational content on our blog: https://growlightmeter.com/blog/

Wondering how much light your plants need? The plant lighting calculator on our website helps you to dial in your lighting to your specific plants' needs: https://growlightmeter.com/calculator/

To ensure an accurate light intensity measurement (e.g. PPFD, DLI, lux, fc, …) , you need to select the correct light source that you are measuring and use a diffuser. Some common light sources are already available for free while others may need to be purchased additionally. In this way, we are able to fund our development efforts and offer the most accurate light meter app out there without annoying ads. For the diffuser you have two options: easily build one yourself for free or get the easy-to-use Diffuser & Cosine Corrector accessory from our website (-> lightray.io/diffuser).

Our Photone Pro subscription enables you to access all supported light sources, measure light color temperature in kelvin, additional pro features, access additional resources for better results in plant growth, and receive our premium support – and there's even more to come in the future!

The subscription is auto-renewable and automatically renews unless auto-renew is turned off at least 24 hours before the end of the current period. Your account will be charged for renewal at the price listed within 24 hours prior to the end of the current period. Subscriptions made on iOS devices can be managed and auto-renewal turned off in Account Settings for your Apple ID after purchase. Once purchased, refunds will not be provided for any unused portion of the term. But no need to worry, you may cancel at any time.

You can find our terms of service on our website: https://growlightmeter.com/terms/

As a proud member of 1% for the Planet we are donating at least one percent of all our revenue to environmental nonprofit organizations. With everything that you purchase from us, you will be giving back!