15-30-15 water soluble fertilizer is a type of fertilizer that supplies twice as much potassium as nitrogen. It is derived from Potassium Nitrate; Ammonium Phosphate; Ammonium Sulfate; Ammonium Nitrate; Sodium Borate; Copper EDTA; Iron DPTA; Manganese EDTA; Molybdenum and Zinc EDTA.