what's SWG?

I have a salt chlorine generator, and its manual recommends 60-80ppm. Right now I'm a little less than 30ppm, and the chlorine level seems stable at "1" (It's supposed to be 1-5). My pool is around 16,000 gallons.

According to the calculator, (after I changed all the units), I need around 3.8lbs of cyanuric acid to get to 60ppm. I have maybe 2lbs of extra cyanuric acid left over from a month ago, so I'll probably just add that and see if it works fine.