I use Red Sea coral pro and like it. I used to use reef crystals and they were good too. They both mix out at decent levels for cal/alk/ and mag. But really there is no best salt.
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20 Gallon SPS reef
29 Gallon FW "fat catfish" tank
20 Gallon Long Dart Frogs "Zig" and "Zag"
You aren't going to get those numbers right out of the can IME. Besides, when you do your water changes, you are only replacing part of the water. The entire system will not have these values.