Thanks for that OM47, I see where you are coming from.It helps in a rare situation Skins but the drop in ammonia is really only a small finesse, it is not the essence of doing things right. Doing things right amounts to keeping the ammonia levels high enough, whether 2 ppm or 5 ppm, to encourage the on going growth of N-bacs to finish out the cycle. In the rare event that a tank starts out low in KH, the lower ammonia value can indeed help you avoid doing a water change or two, but that is not a big problem either way.
Keith.