Consider creating a pond that supplies part of your household's nutrition. You can raise 300 pounds of tilapia in a 1,300-gallon pond---as long as they have enough oxygen. It takes roughly 8 to 12 months for tilapia to reach maturity, so plan accordingly around seasons if necessary. Incorporating a waterfall into a pond oxygenates the water so the fish remain in good health. Set the waterfall up so that it spills into a filter pool of duckweed before it falls into the tilapia pond -- duckweed makes excellent tilapia feed.
Heated ponds make excellent homes for tropical fish such as gourami, betta splendens, mollies, neon tetras, cardinal tetras, archer fish, angelfish, and corydoras. Coldwater ponds are good for goldfish, koi, perch, trout, and bass.
Research the environment the fish you're planning to introduce prefer. Some species, such as bettas, like their water pretty still, so buffer the waterfall's powerful movement with rocks, plants or by adjusting the pump's flow. Species like darters prefer cool water with movement. Try making a shallow stream to connect the waterfall and pond to regulate flow and temperature. Use sand and small pebbles as substrate.
Install lighting in your pond and waterfall for nighttime appeal. Multicolored, clear and solid colors are available at garden centers and through mail order catalogs. Use solar lights to conserve energy. Experiment with rock placement under your waterfall to tune the water's crashing sound to your liking. Remember to use native rocks and plants whenever possible -- they make your waterfall and pond seem most natural.
Grow more than ornamentals in your pond. Try putting that space to good use --- as an aquatic vegetable garden. Try planting aquatic mint (Mentha aquatica), pickerel rush (Pontederia cordata), lemon grass (Cymbopogon citratus), sweetflag (Acorus calamus), Water chestnuts (Eleocharis tuberosa), watercress (Nasturtium officinale), and taro (Colocasia esculenta). These plants can help to feed you or your vegetarian fish species. Aquatic plants sell well now that the locavore movement is growing exponentially, so excess plants and seeds can be sold to neighbors or even over the Internet via postings on local forums.
In this scheme, the fish's biomass helps fertilize the aquatic garden. Also try constructing planting pockets in the waterfall so you can grow edibles vertically. Place stones on top of the roots to prevent plants from washing away before their root systems spread enough to anchor them down.