I've recently discovered that horizontal aeration, plus surface agitation can still leave a little to be desired.
Surface temperatures last week reached 88.5 degrees, and the perch started to act strangely. Yellow perch were observed swimming lazily around the periphery of the pond, and could be caught by hand--never a good sign.
There was obviously a massive die-off of algae and rooted vegetation, so the water had kind of a brownish, smelly characteristic.
I decided that I should run a transfer pump from the bottom of the water column. The pump pulls 250 gpm and the pond was 3/4 empty overnight. Interestingly, the water that was exiting the pond was much darker and much smellier than the pond seemed itself.
I'm not sure about the spelling, but the exiting water smells like "silage?".
We ran a seine and encountered some huge bluegill, and also some still healthy yellow perch. They didn't seem too bothered by the poor water quality, not nearly as much as me anyway. I don't know what to do really, but I'm seriously considering adding a traditional airlift system so the the nutrients don't end up all near the bottom of the pond.
