I have 15000 gallon pool with a Aqua Rite Salt Generator wich I replaced a circuit board in in May. When it was added the salt PPM reading on the panel was running at 3300. After a few weeks the salt PPM went up to 3500-3600 and stayed there unitl this weekend. When I checked it my salt PPM on the display was 4000 PPM. Since I have not added any salt to the water this year, what would cause the PPM on the panel to go up?

The only thing I did different this year from other years was put a chlorine tablet in my pool when the SWG went out to maintian chlorine in the 90 degree weather until I could get it repaired. Chlorine stabilized after system put back in operation.

I have not drained the pool at this point I just don't understand why the PPM has increased without salt?