purple bud auto

You have a bit of everything going on. Looks like the middle left plant with the drooping leaves is being over watered. Let her dry out a bit more than usual if that is the case she will respond by holding her leaf blades straight out again. Start to establish a wet/ dry type watering cycle. The plant in the left front with the curled leaves looks like phosphorus or potassium excess. You should flush her with water. Let her dry out. Don't feed her the same nute strength as your other healthier plants use a lower dose mixture (1/2 dose) until you see new normal new growth then slowly increase her dose. One other factor that can cause theses symptoms is if you use water that has chlorine in it. Some plants can be more sensitive than others and chlorine will build up in the soil over time. If this is the case fill a bucket with water then leave it out uncovered over night or use an air pump and air stone and run it for a few hours to gas off the chlorine. Hope this helps your situation.👍