On 2009-08-25 17:37:03 +0100, Stan The Man said:
snipminants from the water (hence it is cultivated in some
sewage/waste water treatment plants.

Or try one of these -- you might take baby out with the bathwater but
at least you don't have tokeep emptying it:
http://www.garden4less.co.uk/hozelock-pond-vac.asp

Thanks very much for this, Stan. It IS expensive but might welll be
worth it as 2 of our ponds have duckweed and the third doesn't. If we
can get rid of it in those 2, it would be a great boon.
--
Sacha
www.hillhousenursery.com
Shrubs & perennials. Tender & exotics.
South Devon