... , Oxidizer, Petroche SpecificationsPotassium Nitrate is a fully soluble source of K and nitrogen, suitable for use in hydroponics, fertigation ... .03% max Insoluble matter (in water)0.1% max Importance of Potassium in plant growthPotassium is a major plant nutrient and ... is safe to use on a wide range of fruit, flower and vegetables crops.For application rates, seek professional agronomic advice ...