As the temperature drops, you might wonder if you should buy a heater for your Goldfish.
This question was something I investigated myself. The answer is dependent on the kind of Goldfish.
Most Goldfish live in cold water and don’t need to be heated. If a pond is frozen, slim-bodied Goldfish are not allowed. Another reason is that fancy fish should not be kept below 50F because of potential blood clot issues.
This doesn’t mean that Goldfish need to be neglected in winter, especially if they’re outside in a pond.
Keep reading, and you’ll find all the information you need to keep your Goldfish warm and healthy this winter.
Which temperature is ideal for Goldfish?
Most common goldfish are remarkably tough and can survive in water as cold as minus 40 degrees Celsius. To evaluate changes in goldfish metabolism, scientists used temperatures as low as 39°F (4°C). The fish survived without suffering any adverse effects.
Keep Goldfish at 60 to 70 degrees Fahrenheit (16-21 degrees), which is best for fancy Goldfish. You will need to heat your fish if they are fancy. You will need a heater if your aquarium does not have an insulated or climate-controlled location.
What Types Of Goldfish Do do You Need A Heater For?
Many fancy Goldfish are kept for display purposes and require heaters. These include the Phoenix Goldfish, Bubble eyes goldfish and Oranda fish, Fantail goldfish, and Lionhead goldfish.
Remember that all Goldfish may not be the same. They all require different optimal temperatures.
For the Tamasaba silverfish, it is recommended that the temperature be maintained between 60 and 70 degrees Fahrenheit.
Temperatures below 60 degrees Fahrenheit and 75 degrees Fahrenheit will make the Lionhead goldfish more susceptible to infection.
The Butterfly and the Bubble Eyes need warmer temperatures. They require temperatures between 75- and80-degrees Fahrenheit.
Does a Goldfish need a Heater?
Common Goldfish can survive in water below 60 degrees, but fancy species will not. The latter will die if temperatures drop below 60 degrees F (16 degrees C).
Aquarium heaters will be needed for various types of fancy Goldfish like Celestial Eye and Tosakin. Temperatures for the Japanese Tamasaba fish should be between 60-70 degrees F.
Some species, like fantail goldfish, require higher temperatures. They need to be kept at 75-80 degrees Fahrenheit (24-27 degrees Celsius). Fancy Goldfish kept in low temperatures can trigger immune consequences. For example, the Lionhead Goldfish will be susceptible to 75 degrees and 60 degrees, respectively.
Other varieties of fancy fish are sensitive to temperature changes. Bubble Eyes should not be kept in a tank because they need temperatures between 70 and 80 degrees.
Goldfish Breeding Climate
The temperature of Goldfish will depend on whether or not you intend to breed them. If you want to breed your fish in a natural environment, you need to provide similar temperatures as those found in the wild. The species spawns when the water warms after winter.
Your aquarium should be kept at 54 degrees Fahrenheit in winter to encourage pets to conceive eggs. Increase these temperatures by 2-3 degrees per day until your aquarium reaches between 68 and 74 degrees.
Does Goldfish that are kept outside require a heater?
The heater will not be needed for Goldfish left outside. As long as the water temperature doesn’t drop below 39 degrees Fahrenheit, Goldfish can live outdoors. This is because they go into hibernation or dormant mode, stopping eating but remaining close to the bottom of a warmer pond.
This doesn’t necessarily mean that you should abandon your pond. Your pond mustn’t freeze if oxygen cannot enter and carbon dioxide can escape.
A deicer is the best tool to help you do this. Deicers can hear the water surrounding them, ensuring enough room for gas exchange. The deicers won’t completely heat the pond, but they will not affect the temperature.
However, they will appreciate a pond heating system if you are willing to pay. Even though they can survive in low temperatures, it isn’t as enjoyable for them as water at 60-70°F.
What Is Water Temperature Safe for Goldfish?
Common Goldfish is a tough fish that can survive in any water temperature below freezing.
Researchers kept fish in 39F water during one study to examine changes in their metabolism. There were no adverse effects on the fish.
Anecdotally I remember a fish pond in my Georgia backyard as a kid. It was resilient on winter nights, even when it got down to the teens.
This is why common goldfish are better than fancy Goldfish.
Fancy Goldfish need to be heated if water temperatures drop below 50F. Fancy Goldfish can have blood clots or fin rot due to their genetic issues. They also have more trouble in colder water temperatures than common Goldfish.
This is why I suggest keeping your fancy Goldfish indoors in a large enough tank to keep them warm, instead of in a pond.
What is a good temperature for a goldfish aquarium?
In winter, your Goldfish will lay eggs by lowering the tank temperature to 20degC/54degF. To breed hens, raise the water temperature between 20degC/68degF & 23degC/74degF. What about non-breeding tanks’ temperature? If you’re not keeping your fish for breeding, it is recommended that you keep the tank at a constant temperature. The tank temperature should not exceed 23°C/74°F
Avoid placing your tank near sunlight or radiators. This is to maintain a water temperature of 27°C/80°F. Any temperature higher than this will make your fish more stressed. Goldfish thrive in almost cold water. To ensure stronger growth, keep your tank temperature at 18°C/65°F. The tank’s optimal temperature doesn’t experience sudden temperature changes.
Sudden temperature fluctuations can stress your fish or cause illnesses such as swim bladder. It would be best if you also considered the temperature of other fish living with Goldfish. Make sure you choose a goldfish tankmate compatible with the temperature range and other conditions.
What is the water temperature too cold for Goldfish?
Can survive in water temperatures close to freezing.
To encourage strong growth, it is important to keep the temperature of your tank above 18degC / 65degF when you are not trying to induce breeding.
The most important thing to remember is that the temperature in your tank should not fluctuate suddenly.
Sudden changes in water temperature can shock your fish and cause problems like swimming bladder disease.
Final Thoughts
You will see more things you need to know about maintaining healthy temperatures for your fish than you thought. Even though Goldfish aren’t very demanding, some fish require more care than others.
If you are interested in a fancy breed of Goldfish, you must understand the requirements for that particular breed. It is important to ensure that the water doesn’t get too warm.
If you do decide to purchase a heater, make sure to do all the necessary research. You want to ensure that the heater you purchase is durable and affordable. You will ensure that your Goldfish thrives in a warm, healthy environment.