Pond Boss Forums INTRO Questions & Observations Question from a Rookie

The heavy cold rain can dump enough cold, dense water on top of the pond to cause a mid-Summer turnover (or just thorough mixing). If the lower water layers of the pond are devoid of oxygen, the top or entirety of the pond can suddenly have low oxygen. Add overcast, windless days which hamper photosynthesis and don't add O2 through wave action, and not much O2 is added to the pond after the rain event.

Destratification during the Summer via aeration is probably the best defense against this possibility, by keeping the whole volume of the pond better oxygenated.