Well, I took a simple salt test strip to give me a ballpark of salt level, it said I was around 1100PPM instead of the required ~2700ppm.

Now I knew these strips weren't always 100% accurate, but there's no way it could be that off. So I went to Walmart and bought a few bags of salt. Put in 2, let it run for 24 hours then tried the Aquatrol again and everything was perfect.

Guess I shoulda paid more attention to the Aquatrol, because both the inspect cell and low salt lights were on. I panicked a little bit when I saw the inspect cell, when all it was was low salt