Do I Need a Heater for My Fish Tank?

If you have a new fish tank or are considering getting pet fish, you might be wondering if you will also need a heater to keep your fish warm and healthy.

You need a heater for your fish tank if you keep tropical fish in the tank, live in generally cold climates, or use cool water. Insufficient lighting or even a lack of heating mechanisms in your house can also require a fish tank heater.

This guide teaches you more about requiring a heater for your fish tank, which factors you should account for, and what kind of heater you can use.

What Determines the Temperature in Your Fish Tank?

Different conditions and settings in and around your fish tank can help establish and determine the temperature inside your fish tank. You can go through some of these below.

  • Water Condition: Most water sources are likely to give you cool water or water at room temperature, which might work for some fish but not for others. The stillness of the water in the tank can create uneven temperatures, as can insufficient water levels.
  • Lights: Having lighting in, on, or around the fish tank can transfer some heat to the tank itself, warming it up a bit. Placing it near a window that gets bright natural light can also end up warming it up. This can be a good idea if you don’t overdo it.
  • Room Temperature: Room temperatures can vary depending on the presence of coolers or heaters. Ventilation and heat retention can make quite a difference, as can the temperatures outside your home.
  • Climate: Of course, if you live in generally hot or warm temperatures, this is bound to reflect in your house and, therefore, in the fish tank. On the other hand, too much cold or a cold wind can cool down the water and the fish tank, which can prove to be usually unsuitable for your fish.
  • Tank Covers: Do you have your fish tank open or have some covering or lid? The former can keep fluctuating the temperatures inside your fish tank. At the same time, the latter can keep the heat in and maintain the temperatures while also keeping other kinds of contaminants away.

Do You Need an Aquarium Heater?

Generally speaking, you do not need an aquarium heater if you live in warm or hot climates or if you have a heater inside your room that can help warm your fish tank up.

However, to make up for frequently changing weather conditions or situations in which your room heater doesn’t work, getting an aquarium heater can help considerably.

Ultimately, however, one of the most critical factors you should consider is the kind of fish you have. Take a look.

Tropical Fish

Tropical fish need warm temperatures to survive and thrive. Usually, temperatures around 75-80°F are ideal for tropical fish. However, if you live in cold climates, you will undoubtedly need a heater for your fish tank carrying tropical fish. Warm temperatures should also use heaters to maintain consistency across seasons.

Some examples of tropical fish include angelfish, betta fish, catfish, black tetra, blood fin, cichlid, knife fish, swordtail, and more.

Non-Tropical Fish

Non-tropical fish are usually those that can survive in a variety of weathers. Many of these are also cold-water fish that can do well if the water temperature in the fish tank is cool.

You do not necessarily need to buy and use a heater for such fish. However, if you are worried about the temperature getting too cold or freezing, make sure you do some research about the kind of fish you have and the conditions it needs to thrive. On the other hand, don’t let temperatures become too hot either!

Generally, temperatures between 60°F and 75°F can work well.

Examples of such fish include goldfish, loach, cherry shrimp, pufferfish, koi, common guppy, etc.

Should You Have Multiple Heaters in Your Aquarium?

Whether or not you should have multiple heaters in your aquarium can depend on several factors. For instance, how big is your aquarium? If it spans a wide length or covers a large area, having multiple heaters can help ensure consistent and uniform heating.

You might also need a couple of heaters if the one you are mainly using does not work well or requires plenty of repairs. If it might die out anytime soon, having another heater functioning and ready can help minimize damage to your fish.

Do You Need a Backup Thermometer in Your Aquarium?

Ideally, it would be best to have a backup thermometer in your aquarium. While your heater might already have one, it might be best not to rely on that one all the time. This is because it might stop working at any time, or it might not be able to tell you the accurate temperature of the water across the entire tank.

If you are confused about which kind of heater to buy, go through the following options.

Submersible Heaters

A submersible heater is one kind of heater option for your fish tank. These are always kept entirely below the water and either on the bottom of the tank in a horizontal manner or diagonally across the length.

This heater can help ensure consistent heating.

In-line Heaters

An in-line heater is another option for you to consider. It relies on a tube with heating coils and is in the water only up to a particular part of its length. Generally, these heaters might lead to comparatively uneven heating across the tank and be more vulnerable to cracks and leaks.

Final Thoughts

Long story short—you need a heater for your fish tank if you live in cold or changing climates, if you have tropical fish and if the water you use is generally cool. Make sure you take measures to keep the temperature consistent at all times.

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