I dumped the minnows just for forage over the winter. Is that not a good idea? I was afraid that there could be a lack of food.
If your pond is well balanced with bluegills why would you need to dump in minnows? Most of us here consider adding fathead minnows to an established pond an expensive snack as they are slow moving and quickly eaten. Depending on what kind of ducks you have you may have been feeding the ducks with the minnows.
Now a new pond is a different story.