As winter approaches it is time to think about the over wintering of your pond. Now, while the temperatures are above 10c 50f, feed the fish their normal food. As the temperature drops below 8c and 45f feed a wheatgerm food.
You should make sure all leaves that accumulate in the pond are cleared, all plants trimmed including lillies. This is to prevent a build up of gases under the ice if the pond freezes.
Some people recommend you float a ball on the top of the pond, but this is codswallop, the water freezes pushing the ball above the water. the best way is to take a tin, stand it on the ice and fill it with boiling water.