Hi,
Here are pics of a +- 40000-50000 litre pond. The pond is roughly 4(l) X 3(w) X 3(d). It is in Pretoria. Because of the odd shape, I would estimate closer to 45000 litres.
Water Returns:It has a waterfall and 2 venturi returns
Filtration:2 X 1.1kva speck pumps
2 X 3 bag sand filters
2 X 25l ultrazap bio filters
2 X 55w UV's
1 X 50mm bottom drain. 1 Pumps sucks directly from here.
1 X surface skimmer. 1 Pump sucks directly from here through a small settlement chamber.
Koi:13 Koi varying mostly between 50-70cm
Pictures: