You can also follow the advice in this sticky:
https://www.talkbudgies.com/your-bud...te-recipe.html

Do you know his exact age? He may not have been fully weaned, and regressed due to the stress of the move. Millet is an easy to crack seed that baby birds are often weaned onto, so in addition to the electrolyte intake from the advice above, he may be encouraged to eat millet over normal seed.
Give it a try and good luck.

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