I have a Pentair IC40 SWG. I've used strips and the had the water tested and I know that the true salinity is about 2900ppm. My SWG has shut off as it was reporting 4200 ppm. It was giving me a flashing green salt light ( salt level high). This wouldn't be an issue as I just know that it is incorrect, except that it will not produce any chlorine when salinity is above 4000ppm from my understanding. I did a 1 part acid/ 3 part water wash on the cell to try to correct this, and it actually got worse and now is reading 5000ppm. Does anyone know how salinity is measured by these devices? I've looked for a way to calibrate them but not found anything online other than for the older version. I should mention that when I just got started with the pool I didn't know what I was doing and acid washed the cell with straight acid for about 15 minutes. I'm guessing that has finally come back to bite me? Is there a way for me to bypass or trick or otherwise circumvent its self protection? It is worthless if it will not produce chlorine for me, so I'm not averse to tinkering with it etc..... I have replaced the flow sensor last year and I know that changed my salinity level so I'm guessing it plays a part in the determining of salinity somehow?