Pea soup algae grow because there is excess ammonia or nitrates in the pond.
The filter needs to remove the algae faster than the remaining algae can reproduced
due to the excess wastes.
OR, reduce the waste load. How many fish in this 280 gallon pond?
UV doesnt kill the algae, it clumps them so they are less likely to slip thru the
filter. If your filter isnt removing the clumped algae, then they putting the
nutrients right back into the pond. If you put polyester batting into your filter
you will remove that algae, but then you need to take the batting out when it is
loaded and either clean it (squeeze into clean water) or toss it and add more
batting.
A UV filter does work better after the filter if there are a lot of "solids" in the
water. Other "stuff" protects the algae from the UV.
Often the glass in the chamber that holds the UV bulb becomes clogged with algae,
etc. so it is necessary to clean the "window" or the bulb itself. UV lights can
last years as long as other measures are taken to keep waste levels low. Like a
veggie filter.
Ingrid


On Sat, 5 Apr 2008 16:24:00 EDT, lawr_1 wrote:
I only have a 1064L pond (about 1.4m x 1.9m x 0.4m), and have been
trying for a year and half to make it clear naturally. So have pond
plants and a normal bio filter (one of them boxes with foam and
sections of pipes in it). But have failed to clear it naturally so
installed a Tetra 9W 8000L UV clarifier. Its installed just before the
water goes into the filter.