Magnesium Sulphate Heptahydrate 1.99% agricuture grade 2.transparent crystal 3.main contain 99%min 4.special ... . 1. Uses: in agriculture: mainly used in mixed fertilizer or directly used as fertilizer for rubber, palm trees ;2. In industries: used ... .20As ,%,≥0.5Pb ,%,≤1Water insoluble,%,≤0.05 Magnesium Sulphate Heptahydrate fertilizer grade