Kev wrote:
Thanks both!

We live in Scarborough UK, so ground rarely freezes, although a Easterley
wind can be really bitter

Kev


I'm further South than you being in Berkshire......the ground certainly
does freeze here but we are not by the coast.....having been in the
planning stages for quite a few years I've worked out the frost
line.....from my understanding you need to be quite a few inches under
this - mine is about 6" of frozen ice in a bad winter.......Of course
being by the coast your less likely to suffer the severe frosts that we
do.....but I've also seen pics of Yorkshire in winter......dig deep
would be my advice and afterall if you are housing Koi then you need to
do this anyway......IIRC Jan put first suggested the concept of heaters
to me.....take a look at these:-

http://www.aquatics-online.co.uk/cat...r-nets-etc.asp

Gill