It can go either place, but it is most effective when working with the
cleanest water. If it goes before the filter, some will say the filter will
catch the dead algae. If it goes after the filter, the light can shine
further through the water, doing more killing.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html

"colin s" wrote in message
k...
Hi should the uv be before or after the filter?(
pump-filter-uv-waterfall-pond) I have had conflicting advice.
Thanks