We're not sure about the best way to convert the pool to a swan only pond. You would need a way to provide aeration to the pool, clean water without chemicals and we're not sure about the copper/silver ion idea.

Salt water is really not a good idea. Swans, unless they are Black-Necked Swans, do not have filter gland that lets them process salt from the water. Even in Black-Necked swans, this filtering process is very limited. Swans need clean fresh water.

There may be several reasons that the swan likes the pool: He likes clean clear water as opposed to pond water, there is something in the water or the habitat that scares him (i.e., alligator, snapping or soft-shelled turtle, otter, or other predator), or he wants to be close to humans, especially if the humans raised him from a cygnet or juvenile and he does not have a mate.

In any case, chlorine is not the best chemical for ingestion in any species. We would suggest that you find a pond construction expert and inquire into the best way to get clean water without chemicals and provide an aeration method to inhibit some algae and bacteria. Good luck and let us know how this situation is resolved. The Regal Swan