Why are the koi upset? When they scrum around together rapidly, something is afoot (afin?).
The old UV is gone...
...new one is securely in place on the wall and connected.
So why are the koi upset?
Because they didn't get fed! Not to worry, they got their lunch a little late, but dinner was on time. Happy koi. Happy me: the to-do list is now one item shorter.