What is the dissolved oxygen level in your pond?
The Oxygen Saturation Point is a measurement of how much dissolved oxygen is in a water sample. The amount of dissolved oxygen in a pond is important not only for the koi to survive but for almost every aspect of a healthy pond. It is directly related to how well a koi can metabolize food, grow and recover from an injury among other things. Additionally, for a biological filter to function properly it requires a good amount of oxygen. Finally, an abundance of dissolved oxygen in a pond can improve the overall ecosystem of a pond thereby reducing the excess growth of string algae. So, having plenty of oxygen in a pond is directly related to how well the whole pond functions.
Unfortunately, most people have no idea what the dissolved oxygen level is in their pond. The main reason for that is that you need an electronic oxygen meter to accurately measure the amount of dissolved oxygen. Additionally, koi do not give off obvious signs they are lacking oxygen until it reaches the critical level. At that point they start gasping for air at the surface of the water which is a last ditch effort to stay alive. For that reason most koi owners assume their koi are happy.

Where does your pond fall on this chart?
The dissolved oxygen level in a pond is temperature sensitive. Warm water holds much less dissolved oxygen than cold water as the following chart shows. Seldom are oxygen levels an issue during the winter months. Warm summer days and particularly summer nights is where the oxygen level can be a real issue.
As you can see from the chart, unless the dissolved oxygen level in your pond is over 75% your koi could be suffering during summer months if the water temperature rises above 86 degrees Fahrenheit.
With the Advantage Oxygen System you can easily keep the dissolved oxygen level in your pond where, not only the koi, but everything to do with the pond has all the oxygen it needs to thrive all year long.