Looks like a bit of nute burn. Back off on the ec a little bit and should be good. How far along are they? They look well into mid phase of flower. The leaves look wet.. if you are foliar feeding them I recommend you don't as you may cause a mold issue in the buds. They also look a lil over watered, let them dry out before you feed them again.. they will love you for it. Last thing is it looks like you are stressing your plants as evidenced by the 3 pronged (?) leaves..in my limited experience when that happens it is usually due to stress on the plant.. but I'm no expert. Buds look nice