Difference in PPM, which one is correct?

[PoolDoc]

I'm glad it worked out for you . . . and a little surprised that the results are so close together. That does suggest that your actual salt level is somewhere between 2650 and 2850 ppm -- it may not seem like it, but that's a really high accuracy reading!

[waterbear]

Also realize taht the goldine precision is as high as 800 ppm so both your reading AND the pool store reading are in spec!