George, I think you are right on target, One persons desireable plant is another ones pesky weed.I have had days where we removed them from one pond for a customer only to plant them in another pond the same day.Cattails will not over run a pond overnight, like Bill states keep an eye on them and they are fairly easy to keep under control.If they are out of control to start seems to be some good ways posted to get them under control.
