Flourish Phosphorus is a safe solution (4,500 mg/L phosphate) of potassium phosphate that takes the guess work out of phosphate dosing. Unlike other products that mix nitrate and phosphate in a fixed ratio, Flourish Phosphorus (being nitrate free) allows you to dose phosphorus according to the needs of your plants without the risk of overdosing nitrates. When used as directed, Flourish Phosphorus will enhance and accelerate the growth of aquatic plants while beeing safe for invertebrates such as shrimp.
Use 2.5 mL (half a cap) for each 80 L (20 US gallons) once or twice a week or as needed in response to signs of phosphorus deficiency (e.g. stunted growth, plant dark green).