Goldfish love the company of other fish. It is, therefore, not advisable to keep them alone. Goldfish, however, do not move in schools.
In the wild, they move in groups when feeding. There should be a minimum of two goldfish in a tank. This encourages the fish to interact and provides company. Happy fish are healthy fish.
Goldfish can be kept with other peaceful fish such as zebra danios and rosy barbs.