Whats wrong with this plant?

The curling foliage is probably due to radiation burns! from looking at your diary it seems like you're on a 24hr light schedule which may be tempting to use thinking it will increase yields it may actually cause what your plants are suffering from right now which is unnecessary and harmful stress! I'd suggest sticking with the 18/6 light schedule (some growers believe you can even push it to 20/4) since your plants need that dark time to actually burn that energy they produced during the day performing photosynthesis! As for the nutrient issues you're having I already addressed it in another answer to you. Hope this helps! Good luck and happy growing :)