The Green Genie 6500 Filter + 18W UV Bulb from Lotus.

Biological filter and ultraviolet clarifier, designed to provide clean, clear water. The biological filtration uses Dimplefoam and Flocor media to ensure the pond water is kept free of pollutants and provides a healthy environment for your fish and plants. The ultraviolet clarifier reinforces this and maintains clear water in your pond.

Spare 18W UV Bulb available