Smokwirianswered grow question 7 years ago PPM is good,
lower the ec to 5.4 for a week to compensate the high ph level in the coco, lke Athos said, ph level needs to be between 5.5-6,0. This will develop build up of salts in your coco, which at time will be needed to flush out of the system.
you can build up your feeding from 210 to 500 graduatly, when you see recovery in the new leaves, continue feeding at normal schematic
The harm done to the leaves is irreversible, you will have to look at the younger leaves to see how she's feeling at the moment.
I really hope she recovers soon, just send me a pm if i can help you out