drsolo wrote, On 21/03/2007 13:10:
"soil" is composed of different fractions. My students do soil
fractionation in one of their labs. The sand and silt drop down out of
water in 30 minutes or so. The clay, when sitting undisturbed, takes up to
48 hours to settle out so it wont settle out of moving water. Clay can be
precipitated out of water with aluminum sulfate.
http://govdocs.aquake.org/cgi/reprin...1/12010320.pdf
Al2(SO4)3 + 6H20 = 2Al(OH)3 + 6H+ + 3SO42-
however, it is acidifying so dont use it unless your water is pretty hard
already. Ingrid

I'm interested in trying this. The water in our part of the UK is pretty
hard, but I would want to have some lime ready in case the pH dropped
too low.
Would you does the pond with Alum to the suggested 10-30 mg/l in a
single application, or over a few hours/days? If a pH test showed that
the level was down to below pH 6, would you treat with lime immediately
or wait to see if the hard water buffered the change over a few hours.

The PDF suggests 20 mg/l as a lime content to aim for, would dosing it
at 5 mg/l be gentle enough to avoid high pH spikes?

My pond is only about 3500 l, so I'm worried about shocking the fish and
making them ill.

Regards
DavidM


--
DavidM
www.djmorgan.org.uk