... or granular form - full soluble in water - timely delivery Magnesium Sulphate is used as:- fertilizer, tanning, pringting and dyeing, ... form water-soluble Magnesium: 22% min total Magnesium: 27% min water-insoluble: 6% max pH value: 6- Magnesium sulphate .anhydrous (MgSO4) white ... powder MgSO4: 99% min MgO: 32.66% min Magnesium: 19.6% min pH ...