The bulbs do need to be changed at regular intervals to be the most effective. This is the QUATOP UV 5 Watt Replacement Bulb which is compatible with the following AQUATOP products:
- Aquarium UV Sterilizer
- In-Line UV Sterilizer 5W – IL5UV
- UV-5 Submersible UV Lamp
The frequency of bulb changes will depend on which product you own. Stock several as this is a maintenance item needed to keep your tank crystal clear.