Dymax UV-Flo 5W Ultraviolet Steriliser 16/22mm
The Dymax UV-FLO is a quick connect in-line UV sterilizer to easily install along 16/22mm canister filter hoses or even return pump hoses from a sump.
Helps purify water, and improve fish & plant health by:

Eliminating algae in the water
Eradicating suspended bacteria
Preventing the growth of cyanobacteria
Breaking down chemicals

Replacement of 5W UV bulb is recommended every 5000hrs of use.