Thanks for the welcome. I do have one thing to add that may or may not matter. As I stated in my first post, I have a well on the property. The water in the well has been tested and is good. We don't use it or drinking water, only irrigation and etc. but we could drink it.
I have a one inch line from the well to a float valve in the pond to maintain the water level where I want it. I noticed yesterday evening that the valve had gone bad so the pond has been getting a constant infusion of well water at a rate of probably 20 gallons per minute. I have no idea how long this has been going on but I would say at least a couple of months.
Could this have anything to do with the catfish dying? Is it possible that all that fresh water has flushed out some natural elements that the fish needed? I have a stand pipe type overflow with a grid on top so the level has stayed full but constantly flushing. The dead fish look very healthy...well...except for being DEAD.
