Should I do anything special when introducing new fish or plants into my pond?
Generally most pond fish are hardy and tolerate moving well
When you get your fish home, if in a plastic bag, float the bag on top of the pond for 5 minutes, then open the bag and release. If it is an extremely hot day, try not to leave the bag in the direct sun. If your new fish are in a plastic tub/eskie, bucket some of your water into the tub/eskie until the temperature feels the same, then transfer the fish into the pond.
If you have not put any new fish or plants into your pond for over 12 months, placing new fish and plants will challenge the immunity of your existing fish. At times this might result in your existing fish becoming lethargic, sick and sometimes even dying (the longer the period of isolation the bigger the risk).
Using a broad spectrum treatment for your pond at the time of introducing the new fish or plants will be most helpful.
One of the best preventative measures is to place a new fish or plant into your pond every 6 months, that way your pond environment will be constantly challenged, building a healthy immune system to the vast population of bacteria and pathogens that are ever present.