You should not have to drain down the pool because your salt is around 3500ppm. You may need to drain down the pool because the water is laping at the top of the pool deck.

The hose bib above the pump is intended for the purpose of having to drain the pool. Connect your garden hose here and with the pump on, open the hose bib slowly.

What brand of salt chlorinator do you have? How old is it? Post a picture.

-Jeremy