Fish make a great addition to any backyard water garden. Not only are they arguably the most fun part of having a pond, they also keep the water clean by eating insects and algae.
Koi and goldfish are the most popular types for small backyard ponds, and there are pros and cons to both, says Gary Wittstock, president, PondSweep Mfg., Yorkville, Ill. “The smaller goldfish are much hardier,” he says. “They can withstand lower winter temperatures and poorer water conditions.” However, typical goldfish grow only 5- to 8-inches long, whereas koi can grow 2-feet long, which gives them an edge in controlling algae growth. And koi can become tame enough to eat out of a person’s hand.
“But koi do require better conditions,” Wittstock says. They need better filtration and, although they’ll live in 2 feet of water, they prefer 3 to 4 feet. In good conditions, a typical koi can live for at least 20 years, he says. The other plus to koi are the myriad of vivid colors and color combinations they come in, including blue, black, white, yellow and orange.