Phosphorus supplement for the planted aquarium provides the aquarium plant macronutrient, phosphorus enhances and accelerates the growth of aquatic plants this safe solution of POTASSIUM phosphate will enhance and accelerate the growth of aquatic plants without enhancing algae. Takes the guess work out of phosphate dosing. 250 mL treats up to 5,000 gallons. Please click on "more information" for recommended dosage and guaranteed Analysis.