the salinity of the ocean is about 3.5% give or take.
there are 192 teaspoons in one quart of water. so if you put only a quarter teaspoon of salt per quart, you can see that the salinity of that mixture is FAR less than 3.5%, i calculated it at about .001%
the point is that drinking water with 3.5% salt content all day and night would dehydrate you. but drinking water with much lower salt content will do you lots of good.
just remember to get the quality Sea Salt , not the pretnedo-sea-salt you get at the grocery store. i personally believe the himalayan is best.