Yellow leave edges

After reading your other question this was the plant letting you know it was starting to have a Zinc Deficiency growmie. Hopefully, I answered your question and remember Happy Growing and Free your mind one puff at a time.

It could be one of several issues! Over watering, under watering, heat stress (exposed to to much direct sun), or nutritional or PH levels. The plants look fairly healthy though. What feed are you using and what soil? It is essential to allow the soil to become nearly dry before watering each time, you can normally tell by the weight of the pot. Cannabis plants need to be in soil with a ph between 6.0 - 7.0 in order to absorb nutrients. Also the water you use. I use rainwater, where I live it has a PH of 6.5, which is ideal. If you don’t have one you should get a PH meter. I hope this has helped a bit. Good luck.

Light Burn or Light Stress IMO Hope this helps, Happy growing. https://www.growweedeasy.com/cannabis-plant-problems/light-burn