Comet And Common Goldfish In English Pond, Ok...?

[Tokis-Phoenix]

I recently picked up 2 goldfish a couple of days ago, 1 comet and 1 common goldfish, they are living together currently in a sub tropical 30gal(im slowly bringing down the temp as before i got them they were in a tropical tank).
Anyhoo, i was thinking about some ideas on what options i have with them- this summer im building a large pond in my garden, and i was wondering wether it would be ok to move the 2 goldfish out into it when its done ? Im looking at around 1000gals for the pond. Given that over here in england the winters are quite cold.

 

[black angel]

Will it be fairly deep? I think four feet is about right for them to get through the winter ok. They will love it in a pond though.

 

[Tokis-Phoenix]

I was talking to a koi keeper who lives in my street and he said when he built his pond, he got down to 2ft very easily and then there was this thick clay layer for the next 2ft which was very difficult to dig through- ideally i want to get to 4ft deep, but i may have to do with 3 to 3 and half deep if the digging gets too difficult...is 4ft deep the minimum depth or could i settle for 3ft deep? The garden is very sheltered and so far the frosts we have experienced havn't been harsh in the garden.
Hmm...Would an overall 3ft deep pond surfice as long as there was an area in it that was 4ft deep for the fish settle down in during the winter?
Oh! I have another question...
How do common or comet goldfish breed? Obviously i would like more than just 2goldfish, but i dont really want them to breed out of control or anything as i couldn't really reply on them getting good homes if they were to be rehomed...

 

[Mad Duff]

Idealy you want 3' to 4' in depth, the deeper the better really. If you are having trouble digging down you could try digging a couple of feet out and then building the side of the pond up to the depth you want.