As a koi owner, keeping your fish friends safe is one of your top priorities. Because a koi’s sustainability relies on their aquatic environment and is entirely influenced by the water quality, maintaining the water correctly is one of the best ways to care for your koi. With proper upkeep of the pond and water, you will provide your koi with a safe environment to grow and live. 

You don’t need to be a chemist to maintain safe water in your koi pond. Just know the three factors influencing your water quality: physical surroundings, chemical composition, and biology. Physically, the pond is affected by weather and temperatures, biologically, many pond plants can benefit the pond and reduce organic matter, and chemically, the water is filled with many compounds that help or hurt koi fish. This is a guide to the chemical composition in your pond.

WHAT’S IN THE WATER?

OXYGEN

Though koi live their lives under water, they need oxygen to survive. Oxygen that comes in contact with the pond water’s surface dissolves. In order to evenly distribute high oxygen levels in water close to the surface with low oxygen levels at the bottom of the pond, an aeration method, such as a waterfall or pump is needed. Pond plants can also oxygenate the water through photosynthesis. Determining the oxygen content in your pond can be easy with an electronic meter.

pH

pH levels in the pond are affected by hydrogen ions. While koi can tolerate an array of pH levels in the pond, other chemicals such as iron, ammonia, and copper, that are affected by pH levels are not so readily taken by your fish. Generally, pH levels should not be too much of a worry aside from their influence on ammonia levels. A pond’s pH levels can be taken easily with a pH strip test.

AMMONIA

 Ammonia is produced as a waste by koi and is directly influenced by their consumption of protein in the food source. Levels as low as .5ppm can induce stress on your koi, leaving them vulnerable to sickness and disease. Keeping your pond’s ammonia level as close to zero as possible will ensure a promising aquatic environment for your koi to grow to their full potential.

CHLORINE

We commonly know chlorine as a pool disinfectant. It is also found in our drinking water in small amounts. When koi owners put tap water in their ponds, they run the risk of adding this chlorine. Chlorine has negative effects on a koi fish, especially in the gills. The delicate gill tissues can become inflamed, forcing the koi to seek out air at the surface. Koi that have prolonged exposure to chlorine in the water can succumb to disease or even death. To remove chlorine from your koi pond, replace half the water in the pond or add crystalline sodium thiosulfate.

Do you have tips for maintaining your koi pond water? Let us know via the contact form!