You’re relaxing in your backyard, sipping a drink, listening to the waterfall as it cascades into your pond and hear the splashes of happy koi. Then it dawns on you that a turtle would make a great addition to your pond. But can turtles and koi cohabitate? This is a tricky question because technically yes, they can live together but it may take some work on your part and the risk of losing your precious koi. While turtles and koi have their own food requirements, they have considerable overlap and neither the turtles nor the fish have complicated diets. With a little attention to detail and some seasonal preparations, you can feed both species in the same pond.
Be warned though, some turtles are avid hunters, like baby snapping turtles, and may even try to feed on larger fish, which can cause injuries to your fish, like fins and tails. It depends on the type of turtle, as some well-fed turtles won't bother chasing fish while others have a stronger hunting instinct so it is important to research and get a turtle that only eats bugs and vegetation. Getting native turtles to your area will help to keep the turtle alive and healthy. It is recommended to check with your city/state to see if it has native turtles because it may not be legal to introduce a non-native turtle into an outdoor pond. Another caution to heed is that turtles make it hard to control water quality and a safe ecosystem. The turtles defecate and leave bones and tails in the water that affect the clarity and quality and can easily clog the filter. This is why it is important to have a high quality filter that can handle large debris. In addition, turtles are a major source for parasites entering the pond. They also eat vegetation so if you have beautiful lilies or bright colored flowers, they may be destroyed. Turtles also have sharp claws that can ruin pond liners and the base of any pond.
Despite all of these warnings, it is still possible to have both. If you have a pond with koi and still want to add a turtle, make sure to tend to both their dietary needs. Koi are unfussy fish that can be satisfied with pellets as a staple or main food item. It is also suggested to feed your koi "treats" at least once a week. A treat can consist of lettuce, earthworms or ghost shrimp. Feeding occasional treats improves digestion and ensures your koi get all of the nutrition they need. Feed the koi at least once a day and only feed what they can eat in less than five minutes.
Turtles eat a variety of meat and vegetables, and a varied diet is crucial to keeping them healthy. Try not to feed them commercial turtle food as a staple and alternate day to day between a vegetable food and a meaty food. Examples of vegetable foods are feed lettuce and aquatic plants like Elodea and spinach. Types of meats they can eat are live crickets, earthworms and ghost shrimp. Feed them at least once per day.
There is some overlap in their diets so it is not the end of the world if they eat each-other's food, as long as both the koi and the turtles get their share. A good trick is to feed the turtles out of small plastic dishes. Turtles will quickly learn to associate the dishes with food. This allows you to have a little more control over your turtle’s diet. For either species, do not allow excess food to sit in the pond, since it will rot and foul the water.
The choice is up to you. Many people are successful at keeping both happy and healthy in the same pond. Do your research, make sure to get some high quality pond supplies, and enjoy your turtle and koi!