Salt Water level tested at 3600 ppm (twice) at pool test center. My Aqua Rite display shows 2800 ppm. After re-calibrating the Aqua Rite SWG control it reads approx. 3000 ppm, then starts to decrease at approx. 100 - 200 ppms per day until it reaches 2600 ppm at which time the "check salt" and the "inspect cell" lights flash. All other chemical tests were OK at test center. The Aqua Rite T-15 Turbo Cell also tested good twice. The Aqua Rite control displays cell voltage at 2.7V, current 5.26 , 75% desired output, Instant Salinity at 2300 ppm. Approximately, 1 month ago, I replaced the current limiter on the PCB board and it seems to be functioning OK (don't know if that is the cause of the unstable readings). There are no "PCB" error indications displayed.