- A separate germicidal light is enclosed in a PVC body, and when water is passed through the unit, any bacteria, algae, or disease is killed.
- This light does not discriminate what is killed, and cannot be turned on until the aquarium has had sufficient time to build a stable colonies, usually one month is enough time.
- Typically, bulbs will retain their usable life for 18 months. Beyond this time, the amount of UVC light emitted will be substantially decreased. Although some output occurs, the overall effect is diminished, and this will result in more algae, less disease control, and can be detrimental to the overall health of the aquarium.