leaf problem

This looks like heat stress to me along with overwatering. looks like they are not getting enough light either

3 weeks before harvest? im gonna say possible nitrogen toxicity, maybe with a little mix of to high temps and low humidity sprinkled on top.

Without a diary, we definitely need more info, but as Organoman says, she is definitely more than 3 weeks away from harvest, more like 4 or 5.

Probably another 4-6 weeks before harvest maturity, not 3 weeks. Without a diary and/or a lot more information about what you may have or may not have done, it is impossible to give an accurate diagnosis.........too much feeding? wrong feedng? incorrect pH?..........maybe a combination of all three?