Initially, water is the only chemical needed, but monitor the ammonia and nitrites. The filters have been on the pond without fish and food to feed the filter, so the filters will need to cycle to the appropriate level for the fish. If ammonia levels go up, a good ammonia binding dechlor will help the fish get through this part of the start up. Once nitrites show, some salt may be needed to protect from brown blood disease. But for now, just water.
Zone 7 A/B
Keep your words sweet. You never know when you may have to eat them.
Richard