I would add several sheets of blueboard foam (or anything you can get your hands on) to provide shade into the pond. Next I would run the shallower aerators and shut off the deep one completely or move it up 6 feet. Also would shut off the fish feeders and only feed by hand for the next month.
If the visibility gets less than 18 inches I would slowly kill it back or plan on a surface aerator at night as well.
The fish are just stressed with a combination of hot water and low oxygen during portions of the night. The weakest will become delirious and die off. I think you have alot of fish biomass in the pond already with all the minnows.
