I am sure this has been posted many times, so please excuse me.

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.

My present filter is a pair of foam rubber filters in plastic boxes 6x3x3 in
and I have to clean daily.

Martin Oakes