As in nature, fish in a pond eat the plants and algae that grow on the various surfaces in the pond. The fish produce wastes, which settle into the bottom of the pond, where they are broken down by beneficial aerobic bacteria. The bacteria provide nutrients for the pond's plants, which feed the fish, and so the cycle continues.
When the ecosystem is balanced, a properly
designed and built pond will require very little maintenance. A
variety of natural, and fish friendly materials are available for those
times when an adjustment is needed to keep the ecosystem in balance.