For example, according to BleachCalc, for a 10000 gallon pool, adding a 40 lb bag of salt will raise the salt level by 479.9 ppm. Keep in mind that your pool water probably already does contain a couple to a few hundred ppm of salt as well.[/QUOTE]


When I converted to SWG, the product manual suggested about 800# of salt for a 30K gal pool (mine is about 27K), yet I only needed 550# to get to 3200ppm. That would suggest the water had maybe 500-1000ppm salt just through sweat and atmosphere(?). If the calculations are incorrect, please forgive me-I majored in English, not math. My point is, buy some salt test strips and get a feel for how many ppm a bag adds to your pool, because it will always be dropping. I hope this helps someone.
Hal