Tetra Phosphate Minus reduces the key algae nutrient phosphate. Phosphate encourages the growth of nuisance algae such as green water and blanket weed. Tetra Phosphate Minus binds phosphates, thereby helping to prevent the growth of algae and providing a cost effective solution to a common problem. This product is safe for both plants and fish. 250ml treats 5000 Litres (1,100 Gallons) Can be used throughout the year for maximum effectiveness. Dosage Instructions: - Shake before use - Use the dosing cap to add 50ml per 1000 litres of pond water - Repeat dose every 4 weeks if needed