DESCRIZIONE
Pump units for placing in a pond, the unit comprising a housing (40) in which is housed an electrical pump (70), an electrical UV lamp (80), mechanical and biological filters (42, 50, 60) a fountain outlet (90) and bypasses for the fountain and mechanical filters. The unit is arranged such that the pump can draw water from the pond and is operable to cause that water to flow past the UV lamp (80), so as to be exposed to UV light therefrom, before rejoining the pond. [Image Omitted]