I do not use a UV. I keep my fish stocking low,
use plants and don't really mind the beginning
of the year murkiness.
I think it all depends on what you want out of
a pond, how your pond is set up and if you can
wait out green water.

k :-)
http://tinyurl.com/6bguh ~ new pond keeper info
http://tinyurl.com/yp64db ~ slide show of pond