If this has already been posted about on our forum I applogize. There apparently are some buckets of Kent salt on the market with very low alkalinity. Probably no big deal if you know ahead of time and add some baking soda, but if you did a large water change with such a salt you might be unpleasantly surprised. Kent is aware of the problem.
http://reefcentral.com/forums/showthread.php?threadid=807046&perpage=25&pagenumber=3
http://reefcentral.com/forums/showthread.php?threadid=807046&perpage=25&pagenumber=3
