This is a link to my 1.000.000 gallon pond on my farm in Norway. I`m sorry the tread is in norwegian, but the pictures might intrest a few people. The pond is 15 years old, without any fish. But this week my frinds and I have drained it, and "cleaned" it. The plan is to fill it with Koi.
http://nettakvariet.no/forum/showthread.php?t=1060957