(Image removed from quote.) This place is not like it use to be. Later shanty \m/
Tread lightly Grasshopper. If we can forgive a young stranger who crashed our party on ice years ago and then invite him to join us whenever he sees us out there, I think you can let this one go. Whatever "this one" really is. Doesn't sound like anything to me.
Pay heed to the DirectTV commercial:
“When you can't ice fish, you say things. When you say things, people think you have anger issues. When people think you have anger issues, your schedule clears up. When your schedule clears up you grow a scraggly beard. When you grow a scraggly beard you start taking in stray animals. And when you start taking in stray animals you can’t stop taking in stray animals. Stop taking in stray animals.”
Frank, he's thinking of digging a 2'nd koi pond just for them, and run it inline with the current one. Filtration won't be an issue, and if the bait pond is deep enough, temps shouldn't be either. That corner of the yard has good shade in the summer.