My koi have koi pox. I can live with that as I know there is no treatment. I am looking to the future when they pass away and I want to start all over again with new fish. How do I prepare the pond? I expect that I would have to thoroughly drain and dry the pond, change all the internal filter elements, but what else should I do so the new fish I introduce will not get the pox? Should I use a strong cleaner to disinfect the pond? Any advise is appreciated.