08/10/2026
While the rain was much needed over the weekend, unfortunately we weren't surprised when our first phone calls this morning were reports of fish kills. 🎣🌧️
The recent weather in Northeast Texas has created two different conditions that can cause oxygen levels in ponds to crash, and both are common during summer months in Texas (this is a very simplified, Cliff-notes version):
Sudden Heavy Rainfall: After a long period of hot, dry weather, ponds can become stratified, with warmer, higher-oxygen water on top and cooler, oxygen-poor water at the bottom. Sudden heavy rainfall can rapidly mix those layers, spreading low-oxygen water throughout the pond. This is called a pond turnover. (As a side note, this can also be artificially induced by suddenly introducing diffused aeration without properly phasing it in a little at a time!)
Long Periods of Overcast Weather: Several overcast days reduce photosynthesis from algae and aquatic plants, meaning less oxygen is being produced while fish and other organisms continue consuming it.
Either situation can cause problems on its own, but when turnover and cloudy weather happen together, the oxygen crash can be even more severe, sometimes resulting in a sudden fish kill.
Keep an eye out for fish gathering or gulping at the surface, often an early sign of low dissolved oxygen. Unfortunately by the time you notice fish dying, the proverbial ship has sailed and it's often too late for preventive measures.
We'll help you plan for the next time - diffused and/or surface aeration can help prevent this! Give us a shout to find out which option is best for you, based on your pond's dynamics.
