Came home today to no salt reading and the check cell light flashing.
Pulled the cell and it's clean as a whistle. Unplugged it for a while and started it back up, same thing. It appears to be generating (bubbles coming from the return) but not as much as usual. It was working fine yesterday, a little low on salt,2900ppm, added a half a bag that I had laying around. Any ideas?

One more thing, after allowing it to run a while since I pulled the cell it's not flashing a low salt light or a high salt light, I reset the check cell light before checking the cell and it's not flashing either.
We may have had a lightening storm today, but can't be sure.

Sounds like either a blip or it took a while for the added salt to mix and register.

I may have switched it from English to metric unknowingly.
I'm gonna check it out this evening.

Well, I switched last night to metric, no wonder it looked like it had no salt.
I guess 3.2 actually means 3000ppm, in case anyone was wondering.