What Other Fish Can I Have?

[kashifg]

Ive had my pond running for a few years with goldfish.
now considering putting some more fish in, but not sure what my options are.
the pond is a preform type, but an awkward shape , so im not sure how to work out exact volume.
i took a few measurements of the pond:
8.5Ft Length
4.5ft Width
Depth 20 inches.
so i reckon it might be in the region of around 2000 litres.
im running overkill in the filter/pump department, my equipment is the oase biosmart 14000

any suggestions what else, if anything i can put in other than the goldfish i currently have in there?

vid of my pond:
http/www.youtube.com/watch?v=haA5jPtPpTM

 

[fluttermoth]

In all honesty, I'd leave it with just goldfish.

Koi get too large; tench and rudd look attractive from the side, but viewed from the top as in a pond they're just brown, and golden orfe are too active.

It's a lovely looking pond anyway; I'm quite jealous