... ferrous sulphate FeSO4.7H2O FeSO4.1H2O for feed additives, water treatment, Fertilizer, additives for cement etc... ferrous sulphate 1, ... water treatment, for purification of water, for producing ferric sulfate, for iron containing catalyst, or as additive in compound fertilizer ... ---------------------- 0.2%max.; Free Acid ------- 1.0%max.;Free water ------------- 2.0%max.; pH (5% sol.) ---- 2.5min ...