Some LFSs switch salt brands all the time (although one does not recommend the Red Sea brand) Some seem to stick mainly with IO or Kent (which are supposed to be pretty much the same). [I asked 'em]
Of course, this isn't quite as useful to the average reefer because we don't have 1000s of gallons of water to dilute the new salt mix
Just thought I'd throw this little factoid out there.
Anthony