i do not know what is causing your leaf issues, i also see some leaf curl on your latest photographs. it could all be pH related.
here is a pH nutrient availability chart
here is a cannabis leaf deficiency chart
here is the Cannabis Plant and Pest Problem Solver - Pictorial
Cannabis Plant and Pest Problem Solver - Pictorial
here is a meter you may like
https://www.google.com shopping Hanna Hi 98103
here are some searches for pH meters
https://www.google.com search digital pH meter
https://www.google.com search digital pH tester
most pH meters have a 2 point calibration. pour a small amount of pH 7 solution into a plastic bag and dip your meters tip into it, adjust your meters trimmer until it reads 7. next pour a small amount of pH 4 solution into a plastic bag and dip your meters tip into it, adjust your meters trimmer until it reads 4. never let your meters tip dry out. either use storage solution or pH 7 solution in the cap to keep it from drying out. re calibrate your meter every 2 weeks so it is accurate.
i often buy from www.sunflowersupplies.com
here are 16 oz sizes for pH 7 and pH 4 solutions at reasonable prices.
https://www.sunflowersupplies.com/products/GENESIS-PH-7.01-BUFFER-CALIBRATION-SOLUTION-16-oz.html
https://www.sunflowersupplies.com/products/GENESIS-PH-4.01-BUFFER-CALIBRATION-SOLUTION-16-OZ-.html
if you do not have one already pick up a 30x jewellers loop so you can see the trichomes and judge when to harvest.
https://www.google.com search 30x jewelers loop
here is a pH nutrient availability chart
here is a cannabis leaf deficiency chart
here is the Cannabis Plant and Pest Problem Solver - Pictorial
Cannabis Plant and Pest Problem Solver - Pictorial
here is a meter you may like
https://www.google.com shopping Hanna Hi 98103
here are some searches for pH meters
https://www.google.com search digital pH meter
https://www.google.com search digital pH tester
most pH meters have a 2 point calibration. pour a small amount of pH 7 solution into a plastic bag and dip your meters tip into it, adjust your meters trimmer until it reads 7. next pour a small amount of pH 4 solution into a plastic bag and dip your meters tip into it, adjust your meters trimmer until it reads 4. never let your meters tip dry out. either use storage solution or pH 7 solution in the cap to keep it from drying out. re calibrate your meter every 2 weeks so it is accurate.
i often buy from www.sunflowersupplies.com
here are 16 oz sizes for pH 7 and pH 4 solutions at reasonable prices.
https://www.sunflowersupplies.com/products/GENESIS-PH-7.01-BUFFER-CALIBRATION-SOLUTION-16-oz.html
https://www.sunflowersupplies.com/products/GENESIS-PH-4.01-BUFFER-CALIBRATION-SOLUTION-16-OZ-.html
if you do not have one already pick up a 30x jewellers loop so you can see the trichomes and judge when to harvest.
https://www.google.com search 30x jewelers loop