Brown/black spots

hey there AS420 , looks like you could be seeing the start of the potassium lock out and some kind of issue with Mg. I'm guessing it's lock out because you're feeding plenty and complementing with a foliar spray that contained some K. Absorption by the leafs is 80% compared to 20% for the roots. So if you're giving PK through the roots as well as through the leafs it's easy to go overboard. So that explains the colorful discoloration happening with the top leafs first. The fact you're seeing the serrated edges of the leafs turn that's for sure MG deficiency. Right now you're giving two additives and an NPK usually you want one of each, micronutrient (calmag), NPK , and an additive. (Amino Xtreme basically cancels out the Root+ anyway 😉). So if you add calmag now, it's a good idea, hold off on foliar spray containing NPK. or maybe switch to calmag as a spray and dont change too much except slightly reduce your feed. Up to you, hope this helps ! 🚀