Dissolved Oxygen Levels

diffused aeration system increasing the dissolved oxygen levels in a reservoir

In any lake,pond or reservoir, no matter the size, it’s important to have sufficient dissolved oxygen (DO) Levels. Dissolved oxygen is typically measured in parts per million (PPM) and the minimum level you should be aiming for is between 4 and 5 PPM.

Low dissolved oxygen causes fish deaths 

If the amount of dissolved oxygen in your lake or reservoir is lower than this, then you risk any fish within the water body dying from suffocation. Stratification, an oxygen deficient layer of water at the bottom of your pond or lake,  is another possible side effect of low oxygen levels. This can cause plant life within that pond or lake layer to die off and if it is not removed it will rot causing silt and a build-up of nitrate and nitrate levels, eventually leading to a build-up in ammonia. As well as this you risk releasing dangerous toxins into the atmosphere from potential anaerobic waste digestion.

What exactly causes low dissolved oxygen levels?

Large amounts of algae and aquatic plants are the main culprit in causing algae, as they absorb a great deal of oxygen after nightfall. High silt levels will also decrease dissolved oxygen levels in a lake or pond,  releasing harmful gasses into the water. Finally having too many fish in your pond or lake can reduce your oxygen levels not simply through oxygen consumption but also the increase in waste materials they produce.

In a natural, ecologically balanced lake there would be little requirement for aeration but due to the added pressures exerted upon many lakes and reservoirs, during spring and summer especially, added aeration is an essential management tool for most reseroirs, lakes and ponds.

The dependency on oxygen occurs across all levels when it comes to a water body with a healthy ecological balance. This includes fish stocks, microscopic bacteria that are essential for the processing of organic waste, the oxidisation of silt, the processing of harmful gasses or nutrients and a number of other processes.

For more information on how we can help you increase your dissolved oxygen levels please click here.