snrub:
One thing that you touched on is the toxicity of the water when the aeration system isn't being run long enough.
Hydrogen Sulfide is the biggest culprit, and I will see if I can attach a link to an article that is geared towards aquaculture, but it could be applied to ponds. Here is an excerpt from that article:
The 96-hour lethal concentration 50 (LC50) values for
hydrogen sulfide to freshwater fish species range 20-50 μg/L,
and much lower concentrations stress fish and make them more
susceptible to disease. A measure of toxicity, LC50 reflects the
concentration of a compound in water that killed 50% of the test
animals in a specified period of time, e.g., 96-hour LC50.
Ideally, freshwater fish should not be exposed to more than 2
μg/L of hydrogen sulfide for long periods.
https://aquafishcrsp.oregonstate.edu › files › boyd2014hydrogensulfide_gaa
O.K. I don't know how to link to a pdf file, but if you copy the whole line above and paste it into google, the first hit that comes back is the article that I am referring to.
