DO or Dissolved Oxygen Requirements for Your Pond
Every pond has an amount of oxygen available in the form of dissolved oxygen. This dissolved
oxygen varies as a function of temperature, atmospheric pressure and water salinity. Additonally
wind can increase oxygen levels along with natural diffusion at the water surface, while aquatic life and
decomposition of plants can decrease the amount of oxygen in the water. By being able to properly account for
these various factors, you can best determine when to use a pond aeration system to increase the dissolved oxygen
of your pond.
Much in the same way that trout are found nearest areas of the greatest turbulence in a stream, and sailfish and
other ocean game fish are often found in turbulent ocean waters, the dissolved oxygen in your pond will determine
where you fish will locate. By increasing the dissolved oxygen throughout your pond by means of a pond
fountain or other aeration methods, you will see a healthier habitat for the fish and other aquatic life and
greater dispersion of the life throughout the pond.
Factors that can cause rapid loss of dissolved oxygen and create a poor habitat for aquatic life or even worse,
cause a fish kill are as follows:
Pond Stratification - Pond stratification can create areas of
colder stagnant water at the bottom of the pond. This can become a very large problem if an event occurs that
causes the pond to turnover and thus lower the overall dissolved oxygen of the entire pond.
Organic Decomposition - Organic decomposition robs the water of
its dissolved oxygen.
Algae Bloom - Algae can become a great problem if the algae bloom
suddenly dies due to lack of light and oxygen is then taken from the water during the organic decay.
Hot Days - Hot cloudy days can become particularly challenging to pond owners as warmer water is able to
hold less dissolved oxygen.
Cloudy Days - The cloud cover prevents the creation of oxygen attributed to photosynthesis thus depleting the
water of oxygen.
No wind - Wind aids in the process of diffusion whereby oxygen from the air is diffused into the
Days of little wind combined with hot and cloudy days can create a real problem for the aquatic life of the pond
as the dissolved oxygen content will necessarily become lessened. A properly placed and sized pond fountain
can remedy the problems caused by these natural conditions and ensure the health of your pond ecosystem.