http://tinyurl.com/3v4thx
"Agricultural grade gypsum (hydrated calcium sulfate), available from mos
t fertilizer
dealers, can clear colloidal clay problems temporarily. It should be scat
tered evenly
over the surface of the pond at 12 pounds per 1,000 cubic feet of water o
r 525 pounds
per acre-foot of water. An acre-foot is 43,560 cubic feet. To calculate t
he pond’s
volume in acre-feet, the surface area of the pond should be measured in s
quare feet
and multiplied by the average depth of the pond in feet. This figure is t
hen divided
by 43,560. Some ponds built with Natural Resources Conservation Service a
ssistance
have acre-feet volumes calculated and on file. If the pond does not clear
within four
weeks and there is no other source of turbidity, one-quarter the original
amount of
gypsum should be added.

Another material that can be used to clear clay turbidity is aluminum sul
fate (filter
alum). This material will cause the clay to flocculate and settle out. An
application
of about 50 pounds per acre-foot of water will clear most turbid ponds wi
thin a week.
Alum should be dissolved in water and then quickly sprayed over the entir
e surface of
the pond on a calm day since wave action will break up the floc so it wil
l not settle
out. Alum as an acid reaction with the water. If the pond is acidic (low
pH) or has
very soft water, about 20 pounds of hydrated lime (calcium hydroxide) sho
uld first be
added per acre-foot of water. Sometimes this liming will cause the clay t
o settle
out. "

On Wed, 4 Jun 2008 23:15:51 EDT, "D Kat" wrote:

A thanks to all who responded. I think the combination of ideas will fi
t
the bill. I had not known that AccuClear was a flocculent - I will try
to
get some of that this weekend. I just have little mosquito fish in this

pond so I'm not worried about it getting stirred up once it settles. I
did
a search for nylon-wool fiber and could find nothing of use. I then
thought - hmmm maybe that quilt padding I got for a bench might be the
same
thing... I had a bit left over, which I wrapped around the end of the
output hose and that seems to be helping considerably. Of course the en
tire
pond is already lined with white clay... vacuum should work on that...b
ut
then if I leave it and algae grows on it that would be good for the fish
.. I
keep my pump in a bucket of lava rock and that is my lazy man's
mechanical/bio filter. It works wonderfully for most things but this si
lt
was way to fine to be caught in it. Perhaps I should add some of the ny
lon
quilt stuffing to it?

Thanks again and again it is really nice to have this room back (but how
did
the Confidence cassimere crap get through?). Donna