How do industrial-grade and agricultural-grade magnesium sulphate hydrate specifications differ for buyers?

How do industrial-grade and agricultural-grade magnesium sulphate hydrate specifications differ for buyers?
Magnesium sulphate hydrate is graded by purity and end use. Industrial-grade material is specified for electroplating, papermaking, printing and dyeing, and general chemical processing, where consistent purity and low water-insoluble content matter. Agricultural grade dominates volume, supplying magnesium and sulphur to crops such as grasses, soybeans, peanuts, vegetables, rice, wheat, potatoes, grapes, tobacco, sugarcane, sugar beet and citrus. Feed grade supports livestock magnesium supplementation. The hydrate also appears in microbial media, brewing additives, leather filling, fireproofing materials and as a cotton and silk weighting agent. Because the hydrate is made from magnesium oxide and sulphuric acid, feedstock costs and brine availability in regions like Shandong largely set the floor across all these grades.