Leaf edge and tip curled down

hey 👋 I would say double deficiency: primarily potassium, and also magnesium, probably due to a lockout (pH, EC, or both). The soil/coco mix isn’t ideal, those two substrates tolerate different, antagonistic pH ranges ; so I think you’re dealing with a salt buildup here. If I were you, I’d start with a light flush (just enough to clean out the salts) using low-pH water, around 5.8. After that, I’d resume feeding with Bloom nutrients with a good dose of potassium nut not too much nitrogen, and a solid Calmag supplement, all in water adjusted to a pH of 6–6.2. The affected leaves won’t recover, but if the new growth comes out a healthy green within 4–5 days, your problem is solved 👍

iron deficancey...probably

I’m going to say the brown leaf spots and dark green leaves is a bit of nutrient burn. If you’re using chemical nutes, that’s on the strong side. I’d aim for around a 500 - 600ppm nutrient solution.