Used in agriculture as a soil additive to treat iron deficiency (chlorosis) in plants, especially in alkaline soils. It promotes healthy green growth by supporting chlorophyll production. Commonly applied in horticulture for roses, fruit trees, and ornamental plants. Employed in water treatment to remove phosphates and control algal growth in ponds and wastewater systems. Acts as a coagulant aid in the clarification process. Used in the manufacturing of inks, particularly iron gall ink, historically important in writing and drawing. Also serves as a reducing agent in various chemical processes. Found in some dietary supplements as a source of bioavailable iron to treat or prevent iron-deficiency anemia, though less common than other iron salts due to stability and absorption factors. Utilized in the textile industry as a mordant in dyeing processes, helping fix colors to fabrics. Also involved in the production of other iron-based chemicals and pigments.