New light

Also, you may be confusing µmol/m²/s and µmol/J. µmol/m²/s is the measurement of photon flux (PPFD) on a light meter that can measure PPFD (actual growing of the plant). µmol/J is how efficient the diodes are (electricity bill related) as I mentioned in my previous comment.

I believe umol/J refers to how efficient the LED's are at converting electricity to light energy. Lower efficiency LEDs convert more electricity into heat rather than light. For a long time, HID lamps were king when it came to efficiency, but LEDs have recently caught up to lamps. Umol/J is more a concern with electric bills than it is with the actual growing of the plant. A grower is concerned with light intensity which can be measured in DLI, PPFD, or even LUX using a cell phone camera if you are on a tight budget.

You can download mobile apps or purchase cheap all in one light/ph/moisture meters. The app you would look for us a Umol or DLI sensor. Works ok and gives you and idea of your photon footprint and various heights.

Go to the "Migro" page on YouTube and search for your light. They do great reviews and testing of lights so you can see how yours compares. They also have videos explaining light measurement and what the different (PPFD, LUX...) units mean.

Here is a link for you. https://lightsciencetech.com/understanding-photosynthetic-photon-efficacy-ppe/