On 2014-03-06 15:53:23 +0000, Martin said:

On Thu, 6 Mar 2014 15:34:45 +0000, Sacha wrote:

In The Garden of Evening Mists, the woman learning from the Japanese
master is set to making balls out of copper strips. These are thrown
into the pond and sink. He tells her this is to deter algae. Has anyone
ever tried it and I wonder if it would work on the accursed duckweed?

The Dutch used to put powered copper electrodes in the water of their
large boat
houses to reduce weed. It's probably banned now.
There are no fish left in the IJsselmeer because either
a) Over fishing - government version.
b) The water is too clean, so no food for the fish to feed on. Fishermen's
version.
There is going to be a three year ban on fishing.

Bit like putting copper on the keel of a boat to deter barnacles etc.,
I suppose.
--

Sacha
www.hillhousenursery.com
South Devon
www.helpforheroes.org.uk