Supa Filter Wool is a synthetic material that is ideal for removing waste particles in both aquarium and pond filtration systems. The Filter Wool helps keeping the water clean as it is very effective at stopping & trapping fine particles that affect the water clarity. Ideal for use in many types of freshwater & marine aquarium. Filter Wool is sometimes known as Filter Floss. Comes in a resealable plastic tub which helps avoid contamination of the Filter Wool. Made in the UK Directions: Supa Filter Wool is ideal for use in freshwater and marine aquarium filters to remove fish waste and decaying food, which can spread disease if not treated. After rinsing, pack the wool firmly ensuring even coverage across the filter mouth to prevent particles by-passing the wool. Clean periodically in clean water replace if necessary.