Keith, with my fish dying in the goldfish pond, I'm thinking the problem was the fungicide that was sprayed on the corn fields that literally surround my property. Keep in mind I have 6 acres, and my property is a rectangle, but my house and yard are at one end of the rectangle. I read the chemical that was sprayed by plane should not be sprayed within 100' of any water source or runoff area. That was not the problem, as have not had any rain to make runoff since then, except one quick storm last weekend, but no runoff goes into my ponds in any way. I also now wonder if the dying of all of my petunias was because of this fungicide. They have all been dying slowly in the last month, and it's not because of lack of water or fertilizer. Just wondering .... Next year, the farmer will call me before spraying anything on the fields by plane, and I will cover the ponds, and maybe the potted plants, or half of the potted plants, and see if there is any difference. I know there is a chemical that is used to kill flukes in koi, that is DEADLY in goldfish, and pointing the blame to something of that nature. Not going to tell anyone to do anything differently, but AM going to ask to be notified in the future, to keep my goldfish from dying!
It would be nice if you knew ahead of time when they would be spraying for mosquitos, so you could cover your pond as well. I know in towns here, they spray once a month. This is all very upsetting to me, chemicals killing our fish and wildlife, but we don't want mosquitos or fungus killing crops. Not sure what the happy medium is!