"Courageous" wrote in message
...

A while back I saw a post about using UV filters to remove algae. This
puzzles me. Algae thrives on UV from sunlight, so how do these filters
differ? How efficient are they? I have a 120 gal pond and am
considering
a filter which combines a pressure filter and UV clarifier. Nurserypro
Ultraklean 500 gal.

They use intense high ultraviolet radiation, at a band that is generally
inimical to life. The one's labelled "sterlizers" are very efficient, and
will kill your algae dead, dead, dead. There is an issue of what wattage
to use. For your pond (err, bucket?), almost any size will do.

Do keep in mind that the only thing they do is kill algae and other
microorganisms (e.g., bacteria). If you have any other problems with
your water, the UV sterilizer won't help.

These don't help with string algae, just the floating green stuff.

You don't need a commercial filter. Just pump your water under some
fine pea gravel and stones like this:

http://www.pondsolutions.com/bog_filter.htm

Interesting setup.