Hi: Thanks for replying. I actually did clean it yesterday. When I opened it, it didn't look like it had any deposits or scale. But I flushed it anyway. I still have that error. Is there anything else that could cause this? I just bought this house from a guy who had just installed it a few months before, so he really has no clue. All he said was "dont worry, it takes care of itself".

It's strange because when I push the TEST button, the lights are lit as high as the top ones and still the "add salt" lights at the bottom are on also. Could another imbalance cause this? If so, is there a comprehensive test that would detect what demon is haunting my pool?

Thanks, Phoenix