Potassium Sulfate Fertilizer 0-0-53

Potassium Sulfate Fertilizer 0-0-53 is a solution-grade, 100% water-soluble potassium fertilizer (K₂SO₄) that delivers 53% soluble potash (K₂O) and 17% sulfur in a single crystalline form. It is one of the most concentrated chloride-free potassium sources available.

Potassium regulates water movement, enzyme activity, and sugar transport into developing fruit, supporting fruit size, color, firmness, and storage quality. The chloride-free chemistry makes this product well suited to quality-sensitive and chloride-sensitive crops such as tomatoes, peppers, berries, grapes, potatoes, citrus, and tobacco, and to recirculating hydroponic systems where chloride would otherwise accumulate. The 17% sulfur is supplied as plant-available sulfate, supporting amino acid synthesis without a separate amendment.

It dissolves cleanly for soil, foliar, fertigation, and hydroponic use — keep it in Tank B, separate from calcium-containing fertilizers, since combining them in concentrated stock causes precipitation. Pre-dissolve in warm water before injecting, and for foliar use, spray in early morning or late afternoon and keep concentrations modest to avoid leaf burn.

Potassium sulfate from Canada, packed in Madera, California. CDFA registered and third-party lab tested for heavy metals, with results consistently well below required limits.