First off, I am no expert that's for sure. But, bio-mass is bio-mass what ever fish it is I would think. Its sounds to me like a turnover in your pond. Kinda common for this time of year from my understanding. And with only 4 diffusers in a 9 are pond sounds to me to not be enough to properly turn the water over once every 24hrs. This opinion is based on my 3+ acre pond that I have six diffusers which was suggested by two different aeration companies. Reasoning was 6 diffusers due to ponds bottom structure with dips and channels and humps etc. I would think 9 acres might have a bottom of many contours. I have read where or when a pond turnover happens you most likely will lose your largest fish and the pond may repopulate on its own. I also have to mention I experience a large fish kill of TFS once but it was due to a large number of Cormorants where they killed off a couple of hundred 4" TFS along with a few large cnbg and a few HSB that I found in the mix of TFS. There were about 85 cormorants I found on the pond that morning. They do migrate this time of year and a pond like your might be a candidate for Cormorant stop over.

Do not judge me by the politicians in my City, State or Federal Government.


Tracy