You may want to sample the bottom of your pond to see what is happening down there. Is it sediment or muck and how deep? If it is muck, as your water becomes more clear, i.e. crawdad boil, you may want to put a diffuser on the bottom to create more aerobic conditions.
I'll contemplate how to get the sample, but I'm not sure what to look for other than the depth of the muck and how it smells. And, I am confident that my diffusers are circulating the water from top to bottom and getting what DO I have down there .
