What is light burn and how do I stop it?

The leaves right under the lamp go first, while shaded lower ones stay green, which separates it from nutrient burn. Check with the back of your hand at canopy height: if it is uncomfortably hot after 30 seconds, it is too close. Heat stress can mimic the same symptoms, so check temperature too.

Follow the manufacturer's distance chart and dim before you reposition. A dimmable panel like the LEDMAXPRO 300 W makes this easy, and there are more in LED grow lights.