Pond Turnover

Thermal stratification can become a catastrophic problem to your pond ecosystem when an event occurs that creates a pond turnover and this cold water with low amounts of dissolved oxygen is then mixed or turned over in the pond.  This creates a situation where the overall dissolved oxygen in the pond can become so low that the fish and other aquatic life can be stressed or even create a fish kill.  This turnover in the pond is most normally initiated by two events.

1.  When a heavy rain rapidly cools the surface of the water.  This will begin to make the surface water denser, as cold water is denser than warmer water, and the pond water can rapidly mix or turnover.

2.  When a cold front moves in and as in the situation above, the surface water becomes rapidly cooled creating the same turnover effect.

Thus if you ever have a sudden cold front or heavy rain, it is important to make sure your pond fountain or any other aeration system is in working order to prevent a rapid turnover of the water and increase the dissolved oxygen in the pond.