Do Guppies & Koi Get Along?

The koi, also known as nishikigoi, is an ornamental fish developed through centuries of breeding the German carp with the Asian carp. The guppy is a small fish originally from the fresh and slightly salty waters of South and Central America. It now lives in the wild in many parts of the world. While koi do not eat smaller fish and may get along with guppies when put in the same pond, koi and guppies require different habitats to survive and thrive.

  1. Koi

    • There are many varieties of koi. They come in a range of colors, including white, yellow, red, blue and black. Koi are also available in color combinations, such as white and yellow, orange and black or orange and white. In the United States, they are raised commercially in temperate climates. If provided with enough room and food, koi can grow up to a length of 36 inches and live more than 30 years.

    Koi Habitat and Care

    • Koi belong in freshwater ponds, either natural or man-made ones. The ideal water temperature range for koi is 65 to 75 degrees. Koi are omnivorous and will eat a variety of foods, including earthworms, krill, bread, peas, lettuce and commercial fish food. Koi will also eat any vegetation put in the pond, such as bog plants and water lilies.

    Guppies

    • There are many varieties of guppy with a range of colors, patterns and tail shapes. The most common colors for guppies are green, red and blue. A female adult guppy can be more than 2 inches long, while the smaller male guppy is usually 1 to 1 1/2 inches. The average life expectancy of a guppy is two years.

    Guppy Habitat and Care

    • As pets, guppies are primarily kept in freshwater aquariums since they are so small and peaceful. Guppies should be kept in schools, because they are social fish and develop hierarchical relationships with each other. The ideal water temperature for guppies is between 75 and 85 degrees. Guppies eat commercial fish food supplemented with live food such as brine shrimp, blood worms and fruit flies. Guppies like to hide in plants and will experience stress if not provided with hiding places.

    Compatibility

    • Koi have soft mouths without teeth, and are mellow, so they do not pose a threat to smaller fish. While they do not harm other fish, koi are usually kept separate because they are destructive to plant life, which other fish, such as guppies, need to thrive. Koi will eat the plants and muddy the water by digging in the soil around the roots. A guppy's ideal water temperature is 10 degrees higher than that of a koi. Guppies may also have a problem competing with koi for food, because guppies are slower and smaller. So while Koi and guppies do not pose direct physical harm to each other, their different needs dictate that they be kept in separate habitats. When other fish are added to a koi pond, they are usually goldfish, since goldfish also belong to the carp family and thrive in a similar habitat.