A very helpful person took me around a garden once. They had done things to plants just to show me some of the problems that they have.
I am thinking ya got a few things wrong or going wrong.
1 - the leaves will curl and turn brown if you don't have any water and your Humidity is very low. Do you have a dual meter for heat and humidity? If so have you put the temp meter at the top of your canopy to see if your light is too close for heat issues?
2 - Looks like you might have a K (potassium) deficiency or there is too much salt in your soil that might be preventing the uptake of nutrients. Do you have a PPM meter? if so are you documenting it? Do you see a gradual decrease in PPM over a few days or is it staying the same?
Have been growing for a few years and have read every book i can get my hands on, but there is nothing like experience. When ya grow em ya learn, ya mess up now, you wont then!!!!