Whats the ideal temperature for a goldfish tank?
Goldfish will survive quite well in a range of temperatures. My mother had outdoor goldfish as well as indoor, and they survived outdoors even when ice would form in the top (although I think they went into hibernation, and she did break apart the ice to make sure it didn’t go solid). Sometimes the temperature in the summer, either indoors or outdoors (this was Sacramento, California) would get too hot (and you can tell when your fish are too hot as they become lethargic), and we would add ice to the outdoor pond and to the indoor tank. Generally, cooler than what humans would normally like is better, and this can generally be accomplished by keeping the water circulating with a filter, so long as the room temperature itself is okay. Obviously do not keep your tank in the sun or by a heat source or under or above an intake or exhaust unit for your heating / AC. The key however is the temperature change itself. Outside the temperatures changes are gradual enough that the hardy fish will
