Advanced Brewers use MgSO4.7(H20) to improve the wort chemistry as burton salts. Sulfates improve the hoppiness/ hop crispiness and Magnesium gives hardness. Details on dosage here. Please use the packet sparingly. A few gm per batch is all you need.
When making beer, the recommended dosage is 1/2 teaspoon per 20 liters, or use the amount called for by any beer recipe you may be using. 1gram of Magnesium Sulfate in 3.8 liters of water changes the salt levels by 103 ppm sulfate, 26 ppm Magnesium and adds 108 ppm to the hardness.
This is extra pure salt for brewing purposes. Unlike commercial salts, here Arsenic is 0.0005% and lead 0.0005% Zinc and Iron are also less than 0.001%
It comes in powder form which is easy to measure and store. You can use this as a Tofu Coafulant instead of traditional bittern or nigari which usually comes in liquid brine format.