Do Goldfish Need A Heater? (Complete Guide)

Having a goldfish as a pet can make your regular life enjoyable. It will also make you a responsible person as you will need to feed, clean, and understand its necessities on your own. If you are someone who owns a goldfish and wondering do goldfish need a heater then this article is for you, my friend.

The need for the heater in a goldfish tank actually depends on three things. They are-the type of your goldfish, water temperature, and the room where it is placed. For example- a goldfish in a cold pond does not require a heater. But if you keep it inside your room, it will definitely need one.

Goldfish is also known as cold-water fish. That means they can stay in cold water without facing any issues. They enjoy thriving in the cold water. But sometimes under certain circumstances, these cold-water fishes also need a heater. As a responsible pet owner, you should be careful with these needs of your precious goldfish.

Which Type of Goldfish Needs a Heater?

It is a fact that the common type of goldfish can survive in cold water, such as below 60 degrees Fahrenheit. But it is not appropriate for them because it will make the fish sluggish and sick soon. It would not be much active anymore. In easy words, the common type of goldfish also requires a heater in extreme cold, as too much of anything is not good.

Now let’s talk about the fancy goldfish. This type of goldfish can hardly bear the coldness of 60 degrees Fahrenheit, unlike the common ones. This fancy goldfish needs a heater if the tank temperature dips below the 60s F. So now let me tell you in detail by the word fancy which goldfishes are we referring to.

Fantail goldfish:

If the question “Do a fantail goldfish need a heater? pops in your head, then look below.

The answer to this question is also yes. A fantail goldfish usually swims around above 75 degrees Fahrenheit. So if you own a fantail goldfish, then it a wise decision to put a small heater in its aquarium. Otherwise, due to the extreme cold, it can become sick and also even die.

Phoenix goldfish:

If you own a Phoenix goldfish, then you must be someone lucky. As it one of the rarest types of goldfish and hard to find.

Even when it is not kept as a pet too often but like other fancy goldfishes, it thrives at the same temperature. So when the temperature inside the tank, bowl, or aquarium falls below 65degree Fahrenheit, a heater is a must at that time.

Bubble eyes:

The owners of bubble eyes need to be very responsible and careful when it comes to their pet health. Because bubble eyes are very sensitive kind of goldfish.  And tolerating cold water shocks is next to impossible for them. So place a heater in the tank to avoid the mistake of keeping bubble eyes at low temperatures.


If you are making the list of the sensitive goldfishes, then Orandas will take place at the second spot. Yeah, right after bubble eyes. Orandas does not like frequent water changes as they prefer constant water temperature. Their preferable water temperature is between 6272 degrees Fahrenheit. Thus if you want to keep your pet cheerful and healthy, set a heater in the tank.


Doesn’t the name sound Japanese? Also, why wouldn’t it? As Tamasaba actually belongs to a Japanese breed.

This goldfish not only looks beautiful. But it can also grow to a great extent if the water level stays constant at 6070 degrees Fahrenheit. Therefore without a heater, the immune system and growth of this fish will get weak.


Lionheads are not a weak type of goldfish. But the immune systems of Lionheads are also prone to cold water. Their ideal water temperature is also 62 degrees. So alike other fancy goldfish, this one also requires a heater inside the aquarium.

Now, as you know, which type of goldfishes needs a heater. Lets have a look at the commonly asked questions by goldfish owners.

Where should you place the heater in the tank?

You should have a clear concept about where to place the heater. Otherwise, you might end up harming both your fish and tank.

As per expert opinion, you should place the heater in the tank where there has an option of water flowing. In this way, the water will be warm completely, and it will be of constant temperature.

How to set up the heater in the Goldfish tank?

Setting up the heater in the tank is not a complicated process. But still, you have to careful with it. When you found out the exact spot of placing the heater, go ahead. Almost every type of heater has the feature of a suction cup. This suction cups let the heater to hold against the wall of the tank.

Now after positioning the heater, give it at least 20 minutes to adjust. In these 20 minutes, it will also ensure that is the glass stand casing able or not to bear the changing temperature.

How many hours in a day should the heater be used?

Honestly, there is no accurate timetable of using the heater. It mainly depends on the temperature of the water. The hours of heating the tank is not a fixed one. If your room temperature is hot, then you might not need to turn on the heater. But if you place the tank where the temperature is below 60 degrees, then you should use the 24 hours.

What will happen if the heater overheats the Goldfish tank?

Do not think about overheating the tank, even in your wildest dreams. An overheated tank will disturb the metabolism system of the goldfish. It will increase the metabolism of the goldfishes, and as a result, they will eat and produce waste more. The water will get dirty faster, and the oxygen levels will drop. If it continues like this for long, the fishes will eventually die.

Things to consider before buying a water tank heater:


  1. Type of fishHere, the first thing that you should take into consideration is the type of fish. Because if you are stocking a hardier type of then, you need to go for the mild heater. But if your tank is stocked up with delicate fish, then it calls for a powerful one.
  2. Size of the tankThe number of heaters you need depends on the size of your water tank. If you have a large tank, then you should opt for two heaters. When you place the two heaters inside the tank at opposite ends, the water will be equally warm.
  3. Heater tube The tube of the heater should be the length of the aquarium if you want to heat the whole tank. Suppose you bought a heater and its tube is shorter in comparison with the aquarium’s height. So because of this short tube, the whole water of the tank would not be covered.
  1. Placement of the tankThe place where you have kept the tank plays a big role in fluctuating the temperature of the water. For exampleif you keep the water tank in an air conditioner where all the windows remain close. And there is no sign of sunlight. Then you should buy a powerful heater for it to keep the water level at above 60 degrees F.

Here are a few safety tips for using a water tank heater:

  • QualityA water heater is a necessity of a goldfish, and the quality matters a lot in this case. Also, if you go for a cheaper one, it can break out at any moment. Not only may you need to replace it w every now and then. But the sudden breakout can harm your goldfish’s health. So when it comes to water tank heaters, you should not be a miser.
  • InstructionsA heater is not easy equipment that you can just handle on your own. This is why you should know all the instructions for using the heater. Otherwise, you might end harming the heater on your own.
  • Use a thermometerOne of the good habits of maintaining the tank is checking the temperature of the water. You may ask why because your heater is functioning just right. The reason to check the water with a thermometer is to ensure that everything is well. And by any chance, if it’s not, you will also get to know it with the use of the thermometer. It is an inexpensive and less consuming safety tip.
  • Install a temperature controllerAre you a busy person who cannot spend too much time at home? If it is yes, then getting a temperature controller can be your option. A temperature controller can monitor, control, and alerts if anything is wrong with your tank temperature.


Pets are always precious does not matter; is it an animal or a fish. Pets will always be dearest to their owners. As you are today, then you must be a goldfish owner who cares about their pet’s wellbeing and safety.

I hope reading this article will help you big time. As here I have outlined all the necessary information about do goldfish need a heater or not.

Let us know in the comments section below if you have any further queries related to the goldfish tank heater.


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