Manufacturer has confirmed low Ca and Mg levels.
I'll contact them and DF&S to see if there are any other problems with the salt.
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1285879
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1270094
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1265348
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1274357
I'll contact them and DF&S to see if there are any other problems with the salt.
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1285879
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1270094
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1265348
http://www.reefcentral.com/forums/showthread.php?s=&threadid=1274357