First is don't panic and start guessing, trying to do to much at once can create more problems, they will recover and though it may set you back on your grow schedule, you are here and it needs to be dealt with one thing at a time.
Your t5 23w lights can't be too close, they can be within 2" of the plants but your led isn't ideal for cannabis. It is concentratingon a spot and that's what I'm looking at on your plants.
Thing are not going to respond over night but can get worse quickly, light will intensify deficiencies and toxicity so one of the first thing to do when you have problems is give you plants a break and rise the lighting. start by moving that led light to 28" min or turn it off (1 to 2 feet is a big difference in leds), and leave it there for now,leave the t5 were they are, keep up with the no runoff and getting that intake PH down to 6.5 as we talk about, if the plants new growth starts looking better in a couple days drop the t5 a couple inch ever couple days. I'm not a fan of those leds you have.
As far as what the symptoms look like on the leafs for deficiencies I'm looking at trace elements like iron and zinc but before you go adding more you have to get the Ph right because there may be enough in the new soil but the plant can't use it till your water is below 7.0ph. The way to tell if your plant is recovering is by the new growth as old leaf will never recover and being on the top to middle of the plant this should be narrow down to either light burn, PH, or immobile nutrient deficiency but untill you knock them out one at a time you don't know if it's a single issue or a combination.
