-
Step 1
Remove stress from the koi's environment. Stress is the most common cause of disease in koi, since it affects their immune system. Stress can be caused by changes to the water or the presence of predators. Replace the water if necessary, and keep birds, cats and other predators away from the water.
-
Step 2
Quarantine new koi for a three to five weeks so that you have a chance to observe them and make sure they are disease free.
-
Step 3
Study the behavior of your koi. Become very familiar with them, so that you can recognize changes in behavior that may indicate stress or disease. Inspect fish for ulcers and other signs of disease regularly.
-
Step 4
Purchase new fish from reputable sources. Ask for a guarantee that they are free of diseases.
-
Step 5
Clean your pond and don't overstock it. Remove food, dead fish and algae. Regulate the temperature. Treat in the spring and fall to keep disease away.
-
Step 6
Test the pH levels of the water often. Follow guidelines on the testing material to keep the water balanced. Use a UV clarifier and a filtration system.
-
Step 7
Keep koi in a pond that's as large and deep as possible. Water quality and temperature are more stable in a large area.
