The Oxygen level in your Koi pond is something you probably don’t think about very often, but it is critical. To ignore it is a big mistake. Some koi owners don’t understand the need for simple aeration of their pond for the health of their fish. This is even more important in the warmest months.
There are several reasons why you need to pay attention to the oxygen level in the pond. First, its critical for the fish – this goes without saying. But it is also necessary for any vegetation you may have in the pond and most importantly for the critical chemical processes that go on including bacterial decomposition. Every pond has its own unique oxygen demand and it’s constantly changing. It’s affected by the number of fish and the amount of plant decomposition that goes on in the pond.
There is just so much oxygen that can be absorbed into water at any given time. It depends on factors such as the temperature of the water, movement of the water (aeration) and salinity. Since we’re talking about freshwater ponds here, salinity is not a factor to worry about.
Since warm water cannot absorb as much oxygen, during the warmest months of the year, Koi pond aeration becomes very important. Watch the oxygen level in you pond carefully when it gets hot. Keep it at least between 5.0 and5.5 mg per liter.
Good Koi pond aeration is so important to maintaining the proper oxygen levels. Aeration keeps the water moving. Without this circulation the water can become stagnant and the oxygen levels will drop dangerously low very quickly. Fountains and waterfalls are a very common way to keep the water moving.
The amount of algae in the pond will also affect the oxygen level in your pond. Algae will produce oxygen in the daytime, but then at night, algae will turn around and deplete the oxygen. Don’t let algae growths get out of hand.
Remember to try and feed your fish during the cooler part of the day when it is hot. Fish that feed when it is warm utilize more oxygen than when it’s cooler. During the hot part of the day when the water is the warmest, the oxygen level will be lower. This combined with the feeding can bring the oxygen level down very quickly.
Good pond aeration can go a long way toward helping you manage the oxygen level in your pond. The addition of a water feature such as a fountain or small waterfall will provide good circulation and add beauty to your pond.