If they are on a seed diet do you put vitamins in the water? Pellets suppy the best nutrition for birds as they can suffer from certain diseases due to malnutrition. If you are going to try to convert these guys from seeds to pellets you might want to ask an Avian vet as budgies are notoriously stubborn and have been know to starve rather than give in an eat the pellets. I have read that sprouting seeds is a much easier way to improve avian nutrition. Apparently the birds adapt easily to the germinated or sprouted seeds and this process improves their diet by leaps and bounds. Perhaps this is something you might want to investigate. Introduce them to as many different types of foods as possible, fruits, vegetables, cooked rice, just research what is the best for them because some foods can be harmful to these guys.
Finally, talk to them, interact with them, give them out of cage time. Im sorry if I have gotten carried away , overwhelmed you, or sounded like busybody know it all, I just caught a look at those little guys thought were just plain adorable and wanted to help. Im always around and happy to help if needed.
Regards
Sue