overfeeding my friend.
So you suggest i stop giving water for a few days
What are those white spots? Looks like bugs to me.
Not bugs my brother
im new to growing cannabis so excuse me if im wrong but that looks like potassium deficiency. if left untreated it will cause chlorosis and then later on necrosis…
check out this video fully i feel you can benefit from it it will teach you how to identify and treat this issue. https://www.youtube.com/watch?v=KgPvFffsc2I&t=386s
i would just use Ph ed water for a few rounds and no nutes. Looks like you are giving it more nutes than it can handle. After that just use nutes every other watering. More is almost never better
You think it can be the potting soil
@BudWiser, cheers for the indirect information 
Nutrient burn… My guess Nitrogen…