The drought being what it is in Australia, I use stored water for my garden. This attracts alot of misquitoes of course. To keep the larva out of the water I use Rainbow Trout. Raising these fish is a bit more of a challenge than your average Goldfish. It's become a bit of an unusual hobby of mine... here is the result....

The first four images of what i consider "stage one" of at least a three, possibly four stage process. Three water storage "bunts" plus a small pond in the forground.

Water is cirulated via two pumps. One, about 1000 litres per hour, in the bunts, provides aeration in the storage. The second, about 3000 litres per hour provides further aeration and circulation through the organic "filter" consisting of various pond plants.