Well, keeping the bacteria alive is good for you, but it completely destroys this trial as having any sort of validity in my eyes. You have now moved the filter media to a tank with established media and are running it that way. Whose to say that the bacteria that move back aren't ones that were introduced as it ran in tandem with the other filter? At the same time, if it were a completely cycled filter (or very close) and it was now placed on a tank that already had established media, some of the bacteria in that filter should die back. There is no outcome now that would definitively show anything. Certainly it could be argued, but nothing could be truly surmised from this. I applaud your efforts, but this merely goes down as an inconclusive at this point.