Goldfish: These pets come to mind automatically when thinking of a backyard pond. Goldfish have been bred for centuries as hobby fish, therefore there are hundreds, if not thousands of different breeds. They are a good choice for small ponds. They are very friendly and do well mixed among themselves and with other types of fish. We have both read and heard, not to expect them to be as outgoing and friendly as Koi....not so in our pond. Our goldfish are every bit as friendly, if not more so than our Koi. Common varieties for outdoor ponds include, Comet, Calico, Fantail, Moor, Shubunkin and Veiltail. More exotic species include the Lion Head, Oranda and the Celestial. When purchasing your fish, make sure they are at least 2 to 3 inches long. Smaller fish have a higher mortality rate. In an outdoor pond, some varieties of goldfish may reach 10 to 12 inches in length. Under proper conditions, you can expect your goldfish to live about 3 or 4 years; 6 to 12 years is considered a very long life.

Koi: Japanese Koi are not goldfish, they are colorful carp that can be easily identified by their two pair of whiskers, called barbels, on their upper mouth. The different breeds are known for their colors and bred to be viewed from the top. There are single color, two color, three color and multi-colored varieties. Koi grow much larger than goldfish; lengths of 27 inches up to 3 feet are not uncommon. Properly cared for, the potential life span of this fish can be 60 to 100 years old. The oldest Koi on record, lived through 5 generations of one Japanese family, living to be 226 years old.

Other pond fish: Additional fish choices include minnows, guppies, tropical fish and larger game fish. Generally, very small fish do not do well in ponds. They can't compete for food when mixed in with larger fish and sometimes become the food themselves. Tropical fish simply can't take the typical temperature fluctuations like Koi or Goldfish, however if you have a small tub garden, minnows and other small fish work well for both algae and insect control.

Game fish, such as Catfish, Bluegill, Crappie and Bass are available for larger ponds. You should check with your local Parks and Wildlife department because some of these fish might be banned in your area. Many different types of game fish have very specific temperature and aeration requirements, making them unsuitable for backyard pond life.