I have an aquarium housing moors and an oranda. What is a safe temperature range for these fish? There seems to be conflicting information on this online.
My aquarium is in a conservatory and in the middle of winter the water temperature can get as low as 8 °C (45 °F) and in the middle of summer (currently) it can get as high as 30 °C (86 °F).
Last winter I only had moors and noticed no ill effects of the lower temperature. Some online sources seem to suggest orandas are more sensitive to temperature than other types of fancy goldfish, is this correct? Next winter I will most likely heat the water, but to what temperature?
With the increased water temperature in summer the only difference in behaviour I have noticed is that the fish will occasionally go to the top of the tank to get air, presumably due to the hotter water having lower oxygen levels. The use of an air stone seems to stop this behaviour. Are there any other risks at this temperature?