Description https://happyfishlife.com/wp-content/uploads/2023/04/One-minute-with-music-small-size.mp4 UV light helps to kill bacteria and control the growth of algae cell. This revolutionary CHANING Inline UV light is to be connected to the water inlet, similar to the concept of the Inline Co2 diffuser. 3 different sizes of hose connector are provided in the package. It is equipped with a timer and you can be less worried about leaving the UV light ON for too long until it damages your tank cycle. Works well for tank 3ft and below with 3 hrs exposure per day. If you have a bigger tank, get 2 units and connect them together, also consider to increases the exposure time to not more than 5 hrs a day.