I have tried many salts over the years and pay the extra upfront for Seachem salinity, it holds the balance of Alk, Cal. and Mag much longer than any others I have used, thus cutting down on dosing. It does mix up hotter (really hot), has a weird smell at first and can be cloudy, but I think it is miles above the others.
I use it and I am the cheapest guy I know, except maybe Don.