How long after buying goldfish should I wait before feeding them?

Newly bought goldfish need about 3 days to adjust to their new environment, so it is best to wait 3 days after they enter the tank before feeding. This is not absolute – some adapt quickly. If the goldfish are swimming actively, their condition has recovered and the owner can try a small feeding. In any case, avoid feeding immediately after bringing them home, as that burdens their digestive system.