In article , David W.E.
Roberts writes

Hi-tech way is to get a pond heater - just a small heater which floats in a
foam collar - which keeps an area clear of ice.
Lo-tech way is a bucket of hot water to melt a hole in the ice now and then.


I keep the waterfall thing going very gently which stops that end of the
pond totally freezing in winter
janet
--
Janet Tweedy
Dalmatian Telegraph
http://www.lancedal.demon.co.uk