Swans are grazers and will browse throughout the day and night. A Blitz feeder filled with food is more than ample for two swans for at least a week. However, any other supplemental feeding will not hurt them and you can attain this by either dumping the food in the water near you, placing the food on the bank near you (as long as the food is submerged in water if it is on the bank) or you can teach them to eat from your hands (again, water must be nearby especially for bread and poultry layer pellets/cracked corn).

The swans will eat until they are no longer hungry so you cannot overfeed them. Glad to hear about the new pond. The Regal Swan