I've been having problems with my SWG this year. First the cell light was red and it would not produce. Pentair came out and replaced it. Now a month later my new cell is reading low salt. My easytouch says 0 ppm salt. I had my water tested and it was at 3500ppm. I checked the cell for buildup and found none. Tried acid washing it but that did not work. I am dreading calling Pentair as this will be my 4th warranty call in 2 years. Any ideas?