Water filter for cleaner, healthier aquariums - four stage filtration with directional control and flow rate control Removes particulate waste from the aquarium, removes odours and toxic chemicals The good bacteria will thrive on the plain foams within the filter and break down the waste (excess fish food, plant matter, fish waste) to keep water clean and healthy for your fish Comes with an easy to use fixing bracket. The bracket and suckers can be left in place while the filter is removed from the aquarium for cleaning The powerful venturi aerates the water by increasing water circulation and thus the surface area. The venturi is adjusted by a simple rocker switch