I am so sorry for the loss of your koi.
By posting it here it makes us all more aware of how careful we need to be. Thank you for that.
I have a friend who had the auto fill valve on his pond stick open and it claimed 7 of his largest. The smaller ones survived. He didn't realize what was happening until too late... If your pea green pond is crystal clear in 2 days something is up.
Does anyone know why the big ones are more susceptable?
Lori Jo