Used in water treatment to remove impurities and control phosphate levels in wastewater. Commonly applied as a soil amendment to correct iron deficiency in plants, promoting greener foliage and healthier growth in agriculture and gardening. An ingredient in the production of inks, particularly iron gall ink, historically used for writing and drawing. Serves as a reducing agent in chemical manufacturing processes and in the synthesis of other iron compounds. Used in the pharmaceutical industry as a dietary supplement to treat or prevent iron-deficiency anemia. Employed in the textile industry as a mordant to fix dyes on fabrics. Added to concrete to create decorative effects and improve corrosion resistance in some building materials.