What is the preferred temperature for red cap orandas?

Answer 1

They prefer cooler water, so 65-70oF would be fine for them (about room temperature in most homes). They can tolerate warmer with good aeration in the water (to increase the amount of dissolved oxygen).

Goldfish can also live outdoors in northern climates as long as the water is deep enough that it doesn't freeze completely solid, but need a change in their diet to less protein as the temperature cools down, and don't eat once it gets below 50oF.

Answer 2

Red cap orandas like all other goldfish are cold-water fishes and prefers water temperature of about 68-72F.