Hi Gazza, Gerry and Dave,
Thanks for your comments. Looks as though it should be able to cope.
Dave, been there with regard to the electrics. Had a previous, cheaper 3KW unit, which caused problems. Got some advice and found that my 13 amp system wasn't quite enough

Have now got it through a 16 amp circuit.
I have been reading through a lot of the posts in the Koi quest forum and there's a lot of serious people out there. I am more of a hobbyist and enjoy having my fish and don't get worried about all the finer things (not to say that if I had the money I wouldn't be there!). I have had a number of problems with my fish in the past and have only just started stocking with Japenese fish. However, I feel confident now to increase my stock next spring. Consequently, I have a few korean (I think) Koi and some other fish (wife's fault

). Not being too hot on the naming of Koi, I believe that my Japanese Koi are - 2 Nidan's (two step pattern) and a Sumogoromo. You can just see the Nidan's in the picture of the main pond.
I had my pond rebuilt this October and it still requires some esthetic tidying up. The main pond is about 5 metres, by 2 metres and 1.5 metres deep. I have kept the pond at ground level, which gives the advantage of being able to see the fish from the dining room. There is a smaller area at one end for wildlife (fish cannot get to it) and hopefully the pebbles will act as a natural filter. I have some plants which I will update in the spring, the current ones were from the old pond and put in to keep to keep me over to the spring. Hopefully, when things start to grow back and mature, it will look better. The fish seem happy enough though.
I have a 10000 litre pump going into a Cloverleaf 3 chamber filter, the Elecro 3KW heater and currently a Vorton UV.
I will endeavour to put some pictures here, but will be the first time of trying this, so am not hopeful!
[img]http
://freespace.virgin.net/mark.fuller/Photo/Pond%201b.jpg[/img]
[img]http
://freespace.virgin.net/mark.fuller/Photo/Pond%201c.jpg[/img]