Have a AquaRite with T-15 cell. Sometimes (not always) when I run diagnostics, the cell amperage figure does not remain on one number, but rapidly fluctuates. The numbers remain within the 3.1-8.0 range, but instantly change from about 5.3 or so to 5.8 or so. What does this condition indicate? On another related note: with what frequency should I recalibrate the salt level? I usually check it once a week. The initial reading usually stays within 2400 & 3400 ppm range. Should I just leave it until a LED light flashes, or recalibrate at regular intervals? Thanks very much.