Take your sample to another store for evaluation. Invest in a good electronic salt tester for your own testing.

Your salt content should be about 3500 ppm.

They give a reason to shut the system off? Makes no sense. If salt is needed, add accordingly and allow your system to run long enough to completely circulate. Your salt reading will spike temporarily but will come back down overnight.

Maintaining your pH and total alkalinity is important using SWG's. Cyanuric acid levels maintained around 50 ppm is best.

The water may be clear but...