Spots and curling leaves

could be nutes, but also looks like initial stages of light burn. based on runoff ppms, i'd go with nutes and some sort of lockout, but initial stages, so you can easily fix this. You are in soil, so maybe give a ph'd only irrigation, then next cycle of ferts (whatever your normal cycle is) give a slighly diluted dose compared to previously. ~10-15% less? chip away at it because this looks like it's an early / smaller problem that took time to build up. if you look over you labels and calculated ppm of the various nutes you provide... you might be able to make a more precise change to your mix. I have a nute calc, better ones are found online, also a rough set that you can use as a guide in any week of my diaries -- "ppm in use picture." Now, i hav hard water, so what works for your context will likely be different. but, NPK should be around 120-130 / 50-60 / 180-200 ppm, assuming your are far enough into your soil grow that your fertilizer will provide the majority of nutrients.