Keeping Koi Healthy: A Brief How-To

The easiest way to keep your koi healthy is by keeping the water clean, but other factors come into play.  The following is an overview of the some of the most important ways you can protect your koi:

• Minimize stress. One factor in koi illness is stress. Moving into a new pond, overcrowding, or sudden water temperature changes can all stress koi. Stress can knock out their immune system, and then every opportunistic bacteria or parasite takes advantage of the situation.
• Adjust your koi’s environment according to weather. Wintertime brings prolonged cold temperatures that are hard on Koi which can’t produce their own heat to stay warm. When water temps fall, koi literally cannot function; they can’t digest food (so don’t overfeed them) and they have trouble swimming. You can avoid some of the cold-water problems by covering your pond and even more of them by covering and heating your pond.
• Pay attention to your fish. Just like you would for any other pet, be sure to visually inspect your koi. Koi are particularly subject to skin ulcers when the water temperature is in the mid-60s, which is typical of an early spring warm-up or fall cool-down. Koi are subject to external parasites. Parasites are a normal part of life for koi, but they’re not inevitable.