Phosphorus is one of the main three macro nutrients (nitrogen, phosphorous, potassium: NPK) required by plants and can often become the limiting factor to growth in a flourishing system. Flourish Phosphorus is a safe solution (4,500 mg/L phosphate) of potassium phosphate that takes the guess work out of phosphate dosing. Unlike competing 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 Phosphoruswill enhance and accelerate the growth of aquatic plants without enhancing algae growth. For maximum benefit, use with Flourish Nitrogen and Flourish Potassium. Flourish Phosphorus is safe for invertebrates such as shrimp.

Sizes: 100 mL, 250 mL, 500 mL

Directions

Beginner

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).

Expert

The beginner dose raises phosphorus by 0.05 mg/L (0.15 mg/L phosphate). The ideal phosphate level will vary, but generally ranges from 0.151.0 mg/L. Use MultiTest Phosphate to monitor phosphate levels. To target a specific phosphate increase, dose according to the following formula: 0.8vp=m, where v= volume of tank in gallons, p=desired phosphate increase and m=volume of product to use in mL. For example to raise 20 gallons to 0.1 mg/L phosphate you would use: 0.8*20*0.1=1.6 mL.

FAQ

I thought phosphates were bad and could lead to unwanted algae growth. Why would I want to add it my aquarium?
A: This is true, but only when phosphorus levels become excessive, that is, when there is more phosphorus available than the plants can use. When this happens, it becomes available to algae. Phosphorus is still vital to plant growth, though. Flourish Phosphorus should be used in cases where there is a phosphorus deficiency.