How to measure lumens of a full spectrum LED light.

you can not use a lux meter to measure "photons". It measures Brightness that is all. It's horrible and inaccurate. I have a Quantum Par Meter and while not a "viable" option for everyone it's the only to meter light.. If I compare it to a lux meter.. The lux meter is absolutely useless... You are most likely experiencing higher rates of transpiration and not actually "too much light". I assumed when I was first using leds that the Light was too close.. While the light being close can be a culprit.. It has more to with Water and transpiration then it does to do with "too much light".. IE. Iv'e had cannabis in ranges from 800-1300 Umols and had it display near zero issues. Iv'e also throttled out a couple plants by having too much light and not enough water. We are growing living creatures so learn to listen to your plant :).