Well that is very cool! I don't think I could put down fish . . . no, I know I couldn't. And I don't know what I'd do if the problem presented itself. Thankfully, it hasn't. Don't ask me why, but my silly goldfish in the big pond haven't had any offspring for years . . . and the ones in the little pond always seem to get eaten by something before they become a problem. (once it was a snapper, once it was birds, got a lotta frogs up there and a snake or two visiting, etc).