| UV lights have been placed in the settlement chambers of the japanese at the beginning of the filter system, while european, american hobbyists tend to place them at the end of filtration as they dump back to the pond.
I don't use one and my water is crystal.
bulbs need to be changed on an annual basis and the sleeve cleaned as well.
I believe the reason in different parts of the world useing different placement is because they have a different purpose. In the states, it's to control green water.
in japan it's to eliminate bad bacteria before it gets thru out the system. |