Hi all,

I have a large outdoor fish pond (and a typo I just did, a fish
pong, which it does if you stir it up) that gets a lot of sun, so
made an algae killer with a 10W UV-C germicidal lamp

http://dl.dropbox.com/u/18683201/UV-C_algae_killer.jpg

(very reminiscent at night of Mr Burns in The Springfield Files.
Maybe I should call it Burnsy)

As you can see, it will turn pea soup into clear water by
giving algae the Sunburn From Hell, which causes it to clump
in fluffy bits about 1mm big. That is the brown muck which
accumulates and needs flushing out. It's pretty 'sticky' too
and gradually coats anything it comes in contact with

During the day the pond is murky because of this dead algae
generally scattering sunlight, but a night flash shows that the
water itself is pretty clear. Water is about 80cm deep

http://dl.dropbox.com/u/18683201/day_night.jpg

So I was looking around and found this site

http://www.simplecentrifuge.com/gallery-series-17.html

A high-speed centrifuge seems to a fairly good job of
removing the very light live algae, so it should be at least as
good with these bigger particles

The question is though that some manual effort seems needed
to periodically remove the sludge and I'm wondering if anyone
has seen an automatic method that could be built at home. I
don't really have room for a settling tank, and have to keep the
health of the fish in mind too of course

Any thoughts or suggestions appreciated

I've thought about trying back-flushing, electrostatics (could
that be done in water ?), gravity, but not filtering. Filters clog
quickly and are just too high-maintenance

Joe
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