The AlgClear UVC 5000 from Ubbink keeps your pond water clean and free of bacteria that cause algae growth by means of UV light. This UV-C unit can be used in combination with pond filters (not included) that absorb accumulated algae. It is suitable for ponds with a maximum capacity of 3.000 L/6.000 L (pond with fish/pond without fish). The calculation of the performance of the pond purification capacity to be selected according to the volume (l) of the pond with/without the presence of fish is as follows: For ponds without fish: 1 W UV-C power per m³.For ponds with fish: 2 W UV-C power per m³.For ponds with koi carp: 4 W UV-C power per m³.