I bought Culligan brand salt at Costco which stated it is 99.6% pure. I dumped a 50 lb bag my 13,000 gallon pool and to my horror as I was getting ready to add a second bag i noticed in the corner it says "with sofner gard II" I did a Google search to see if I could find an MSDS sheet for what is in "sofner gard II" but could not find anything. Does anyone know what is in it, is it a small enough about I can not worry about it or am I about to drain and fill again?