Well that was only one fish. He's called a "shooter" in the aquaculture business. I put him back hopefully to be re-seined when I am ready to move a few thousand into the house. He's one that needs to end up broodstock.
I'm surprised you didn't keep that shooter and put him in a small tank so you don't take a chance on loosing him.
Is that leaking tank the one you used in your basement or a different one?