Help needed

Hi guys,what’s causing this and how do I correct it

Looks like light burn.

If ur lights are correct it could be potassium deficiency. Check to see if you might have fungus gnats in your soil. Whenever they are in the soil and larva eat at the roots, they lay there eggs and eat at the roots. the plant doesn’t release potassium to the leaves cause it keeps it at the roots to protect it from Dying. Good luck