Koi are delicate fish who must be fed and cared for very carefully which means taking good care of their environment. Below are a few tips to keep your koi happy and healthy for many years.
Water
The water in your koi pond is the main environment for your fish and as such should be carefully monitored. The first thing you want to keep an eye on is constant temperature change and while you cannot control Mother Nature, you can take steps to avoid very hot or cold temperatures in your pond. Unless you live in the extreme south, you will want to install a water heater for the pond. The only thing you can do for extremely hot temperatures is build a pond that is deep enough for fish to find cooler spots and provide shade for your pond. Shade can be accomplished by placement or by building an arbor. Beware of placing the pond directly under trees that can shed leaves into your pond. The leafy matter will fall into the pond and decay causing additional headaches for pond maintenance.
There may come a time when you need to change the water in your koi pond, but remember to do this slowly and gradually. If you are using regular tap water that contains high levels of chlorine or other salts be sure to treat it accordingly before adding it to the pond. It is also important to keep the water moving or aerated. You can purchase a fountain to do this for you but many people simply add a waterfall for aeration and aesthetics.
Health
Koi are delicate in some respects however, they have a hardy immune system. This does not mean though that they will never become ill. Watch for signs of illness constantly so that you can remove the affected fish and treat it immediately with the appropriate medications. When koi do become ill, the likely cause is stress, which lowers the immune system. Stressors include but are not limited to parasites, over handling, poor water, chemicals or improper feeding. Keep a close eye on these and other common stressors to protect the health of your fish.
Food
Koi should be fed twice a day in five-minute intervals. Choose their favorite food and then offer all they will eat for a five-minute period. These feeding periods should be at nearly the same time every day and can be tapered off for the winter hibernation period.
Conclusion
Creating a koi pond is pretty simple but as with any type of pet care, it can be a job to keep the fish healthy. Along with the above tips, you will also want to monitor ph levels in the water, keep an eye out for predators especially birds, and place enough koi in the pond so they can socialize but not be overcrowded.

