WE faithfully add salt every year in the fall since 1997.
First we remove the plants and take the in plants we are
over-wintering. We use kosher salt -- about 25 lbs, in our
2500 - 2800 gallon pond.
We dissolve about 3 lbs of the salt in a large bucket of pond
water and slowly add it while walking around the pond. Do do this
over a months time, usually by the beginning of November all the
salt is added.
We have only lost one fish (in 14 years) in the winter of 2009. He didn't look
sick, so we believe he jumped and hit his head on one of the rocks
on the edge.
this was taken in Oct 2005, after salting the pond.