The Oase ProfiClear Premium XL discharge module (gravity-fed) is designed to accommodate the pump that returns the filtered water to the pond. It can also house the new Bitron Premium UVC clarifiers where the final stage of filtration takes place. 
 
On the other hand, the Oase ProfiClear Premium XL discharge module (pump-fed) comes with the Oase ClearWave, a fixed bed filter that provides additional biological filtration by using bacteria to eliminate harmful toxins. These modules are built-in with an air-stone, which allows further aeration to be achieved by simply connecting the air-stone to an aerator pump.
 
Oase ProfiClear Premium XL discharge module (gravity-fed)
Minimum flow rate 25,000 litres per/h
Maximum flow rate 66,000 litres per/h
 
Oase ProfiClear Premium XL discharge module (pump fed)
Minimum flow rate 25,000 litres per/h; 
Maximum flow rate 50,000 litres per/h