Background info: When we bought our house in 2002, it came with a small koi pond. Over a year later the rubber lining developed a significant leak. Since we were forced to tear down the waterfall to replace the lining we decided to remodel the pond to accomodate more koi and a more natural looking waterfall. We contracted with a local company to create a new pond and waterfall. Another contractor did the edge rocks to match the patio. The original pond was 4'x6'x26" and stood out 18" from the retaining wall behind it; it had a rubber liner, submerged filter and pump. The new pond is 8'x9'x3' and is recessed into the fig ivy covered retaining wall, has a leak-proof spray-in lining, a bottom drain, venturi, skimmer with UV, external pump and hydrobead filter. The waterfall is 5' tall and has 6 separate water outlets to provide a balanced flow. As of June 2007 we have 9 koi in the pond, the largest measuring 32" in length.