How to Choose the Right Aquarium Heater

If you’re looking for the right aquarium heater for your tanks, then you have come to the right place. Here at Pond Planet, we are proud to offer a wide selection of premium-quality aquarium heaters, which promises designs to suit every aquarium. But with so many options on offer, which aquarium heater do you choose?

To help you find the right aquarium heater for your tank, we have put together the all-you-could-need guide on choosing the perfect aquarium heater. From basic facts to helpful hints and tips, our extensive guide has all the information you need to make an informed decision on your aquarium heater. So, read through our guide today and browse our selection of high-quality aquarium heaters online now.

Do I Need an Aquarium Heater?

Firstly, let’s cover the obvious, and that is, do you need an aquarium heater? The short answer is yes. 

Most fish are cold-blooded animals, and they rely on their surrounding waters to regulate their body temperature. Similarly, the majority of freshwater fish are tropical species that prefer warmer waters, and so if you like to keep your home at a cool temperature, then you’re going to need an aquarium heater to ensure water temperatures stay warm and steady. Keeping warm temperatures also ensures a less stressful environment for your fish and therefore helps to prevent some diseases!

What Size Aquarium Heater Do I Need?

Next, you may be wondering what size aquarium heater you will need for your tank. As a general rule, we recommend that you have 1 watt (W) of heat for every 1 litre of water. This is based on having your aquarium water heated 10 degrees above room temperature and ensure you utilise the aquarium lid for retaining warmth and preventing evaporative cooling. So, with this in mind, we can theorise that a 100-litre tank under these conditions should have a suggested heater size of 100 watts. If you feel as though your house is generally kept on the cooler side, then you may want to reconsider these parameters and up-sizing to the next available heater size.

What Else to Consider…

Other factors that may affect your aquarium temperature to consider include where your tank is placed in your home. The temperature of your tank is going to differ greatly depending on where it is placed, for example, from a tank being in the basement of your home to one being placed in a sunny room. You also need to remember that heat rises, and so if you have an aquarium rack, any tanks placed on the bottom shelves are going to be cooler than the tanks at the top. All of this needs to be taken into consideration when choosing tank heaters!

Types of Aquarium Heaters

When it comes to aquarium heaters, there are a few different styles and types on the market, including the four most popular options, submersible, immersible, substrate and filter heaters. Beyond these four there are other options, such as in-pump heaters, hanging heaters or heating mats that sit underneath a tank. However, some of these are not recommended, especially the likes of heating mats which have been known to malfunction or stop working completely. You would also need to drain the tank completely to remove or swap the heating mat, which is not recommended!

With this in mind, we are going to cover the four most common and popular aquarium heater types so that you may have a good idea of which would be best for you.

Submersible Heaters

Designed to be placed fully into the water of your tank, submersible heaters are generally long, slender and round in shape. By attaching to the walls of your aquarium by clips or suction cups, you can position the heater horizontally, vertically or at an angle. However, we recommend keeping submersible heaters away from gravel as it does not conduct heat well and may lead to causing the glass of the heater to crack.

Immersible Heaters

Immersible heaters feature a glass tube with a heating element that winds around a ceramic or glass insert. Some immersible heaters may also contain sand.

The placement of immersible heaters depends on the type that you choose, so take this into consideration before purchasing. Some are able to be fully submerged, whereas others, often referred to as hanging heaters, can only be partially submerged. Usually, they have a clear water line marked and must not be put into the water lower than this point. They get their name as they hang from the top or the side of the aquarium.

Substrate Heaters

If you are looking for an aquarium heater that can be almost completely hidden, then you may want to consider a substrate heater. Also known as a cable heater, substrate heaters utilise a flexible cable with a heating element that can be buried beneath sand or gravel. Although it is one of the least common aquarium heaters, some aquarists believe that it is the best option to use within planted tanks where the gravel should be warmer for ideal growing conditions for plant roots. 

Substrate heaters work by warming the gravel, which then radiates heat to warm the water. It is best to be placed in a zig-zag formation to ensure even and optimal heating.

Filter Heaters

Other heater options to consider include filter heaters. You may have noticed when choosing your aquarium filter that it has an inbuilt heater and so you should take advantage of this. These tend to most likely be canister or power filters and perform the double action of heating the water as it goes through the heater. This means that you have continuously pumping warm and clean water in your tank.