Is it possible that the original stocked fish (and added LMB) have grown to the point that the pond's carrying capacity was achieved?

Just a thought that runs through my head as I watch my fish grow (year two) and try to plan my culling efforts.

Running the aerators more sounds like good insurance, just watch your water temps as summer kicks in so that you don't over heat the pond. Warmer water carries less DO. I can't prescribe the balancing act here, but I can say that I TRY to keep my pond from getting warmer than 85 degrees F at 18 inches below the surface.

Rain will usually knock the FA in my pond back down below the surface, But I think it rises back up. I don't let it stay in the pond if I can help it. I rake it out.

Here are some questions to answer that may help others with more experience add to your thread...

1.) Can you estimate the numbers of fish and types with average sizes that are in the pond? Ultimately, a total number of pounds of fish in the pond would be good to know.

2.) Describe your aeration system...pump size, diffuser type and quantity, & diffuser depths.

3.) Any water chemistry that you have available.

4.) Water temps throughout the column.

5.) Are Turbidity/Clarity measurements available?

6.) chemicals being used around your property (fertilizers, pesticides, herbicides)?

7.) Are there any signs of illness/stress on the fish?

That's all I can come up with at this point other than the benefit from losing several pounds of fish IF it was a DO crash is that there is less biomass for the pond to support now. That may not be very comforting, but it does lessen the likelihood of it happening again right away.

Fish on!,
Noel