Well, lets start with CYA and Liquid Chlorine... get that in there pronto.
Lets start with 70ppm of CYA...Per PoolMath that would be 71 ounces of granular CYA stabilzer in a sock hung over the edge in front of a return.
To match 70ppm of CYA for chlorine you need to aim for 6ppm of Free Chlorine (FC) so that's 58 ounces of 10% Liquid Chlorine.
That gets you started and safe while adding salt.
Keep the SWG OFF when you add salt, and for a day after.
Add however much salt as your device requires. I'm assuming this is a fresh fill so no salt currently in the water.
Use PoolMath to tell you how much salt you need to get X amount of ppm salt.
Then follow the guide here to let the device maintain your FC for you -->
FC/CYA Levels
Any time you need INSTANT increase in FC use Liquid Chlorine rather than boosting up the SWG. SWGs work too slow to fix immediate problems.
Maddie