What's going on?

My plants are about 4 weeks into bloom and they have been getting rust spots on the leaves and some of the leaves at the bottom began to get pale. Last few days there have been quite a leaves that have just feel of, the ones that feel are very pale green, they looked nitrogen deficient , put my ppms are at like 1400. Ph 6.1. Tops look fine, just not sure what's going on. The rust spots are climbing the plant slowly. Already added calmag thinking it was calcium deficient. This had no effect on stopping the spots.
 
Top