Hello fellow grower. That to me is looking like nutrient burn from too high of a ppm. Or it also looks similar to an improper range of PH. Simply water with PH of 5.5 - 6.5, allow the water to run off through the potters, and then repeat until the runoff measures in a healthy range of 1000 to 1200ppm and the ideal PH range. Hope this helps! ✌️