Managing a lake or pond is hard work and there are many variables to keep track of. One that sometimes gets overlooked is the role oxygen plays in the health of your ecosystem. There are many areas in which oxygen has an effect.
Flow rate is the rate at which the water circulates throughout your pond. It is calculated in liters per hour (lph). If your rate is too low, that means your water is stagnant and your pond can be more susceptible to unwanted influences. If the rate is too high it can be stressful for your fish and increase the turbidity, or haziness due to floating particles, of your pond. Managing a proper flow rate can be accomplished with pond aerators and fountains.
Measuring the dissolved oxygen in the water can also give you an idea of the flow rate or aeration of your pond. You should find at least 6 parts per million (ppm) present. Almost everything uses dissolved oxygen: fish, other animals, decaying matter and plant life. Basically everything that has a respiration process. If your dissolved oxygen level is too low, you may notice an algal bloom.
Temperature and time of year have a direct relationship with the amount of oxygen available. A water temperature of 60-78 degrees in the spring, summer and fall is ideal. Lower temperatures hold more oxygen and higher temperatures hold less. Higher temperatures also mean there will be increased demand for oxygen or the respiration processes of living things in your pond.
Oxygen is super important for all living things, including us! A healthy pond supports all kinds of life, so it makes sense that maintaining proper oxygen levels and flow is necessary. Aerating your pond prevents a lot of other problems, so go get yourself a nice fountain!