I've cleaned it with the ma and with the vinegar as the manual says. I've added a little salt at a time and tested it by turning it on, but the same thing. I've now added a whole bag of salt - no, I don't know the exact number, but strips are on the way. Everything was just fine. We did get some heavy rain, but it was still fine until about 3 or 4 days later. Then suddenly every time I turn it on after about 2 minutes I'm getting "91" low salt. I started getting concerned that I could have left the ma in too long and ruined something, but this was happening before I cleaned it with ma. I'm at a loss. I'd like to get it fixed and get the water where it should be before I close the pool. I just got this in March. It really should last more than one summer. Any ideas would be most helpful.