How ultraviolet sterilization works
Ultraviolet light is capable of eliminating algae spores in the aquarium. The UV steriliser consists of a UV lamp fitted inside a sealed quartz sleeve, mounted within a water jacket. Aquarium water is fed into the outer jacket and sterilised as it flows from one end to another. The lights efficiency can be enhanced by pre filtering the water before it enters the UV light. This prevents organic matter and suspended materials from obscuring the quartz sleeve creating better UV penetration. The UV lights will need to be changed every 6 months with some lasting for a year.
This is a typical UV unit used to treat aquarium water. Do not look directly at the UV light and this will damage your eyes.