2 litres Blue Horizons Long Life algicide.
Contains Copper Sulphate and Polyquaternary Compound.
A highly concentrated algicide to prevent and control algae.
Dosage 2 litres per 90 cubic metres (2litres per 20,000 gallons).
One dose lasts 3-6 months.
See the advice section for information about the different types of algicides.