Best Aquarium Heaters to Buy: 2019 Reviews and Guide

best aquarium heaters

As a fish keeper, you need to be aware that fish are different from human beings in the sense that they cannot control their own body temperatures. And for this reason, it is absolutely necessary to have the best aquarium water heater together with aquarium thermometers in place to help the fish get the required stable water temperature necessary for their survival.

We have the majority of the fish we keep in our fish tanks requiring warm water for them to survive. This means that unless you stay in a place where it is warm all-year round, you need a fish tank heater to keep the water temperatures stable for the fish. But getting quality water heaters can be tedious and tiresome, especially in the face of the many fake aquarium heaters in the market today. But with concise and unbiased aquarium water heater reviews, one can be sure to get a good aquarium heater to serve his purpose. This article provides an unbiased fish tank heater review, to enable fish keepers to find the right heaters with ease.

Importance of aquarium water heater

The need for an aquarium heater is a necessity, for as long as you rear fish and the temperatures in your locality keep changing. The heater will help replicate the natural environment as well as the conditions necessary for fish survival.


With an aquarium heater, you can be able to raise or lower the temperatures of your fish tank to appropriate levels, depending on the fish species that you have.

It is particularly important to have a water heater in your fish tank as the temperature changes have an effect on your fish. In most cases, the changes bring stress to the fish, and if this stress is persistent, then it can have fatal consequences. We need to remember that large water bodies such as lakes and seas have their temperatures relatively constant.

And one needs to note that while people in some countries will be dealing with low water temperatures, in other countries, people will dealing with high temperatures and will thus need aquarium water coolers for their fish to survive.

Things to consider when buying the best aquarium water heaters

Before you invest in a water heater, it is important to know a number of things that will determine which type of aquarium heater to buy. Below are some of the things to consider;

Size of the aquarium tank

The size of the aquarium tank is an important factor when deciding on which type of heater to buy. This is because if you have a large capacity aquarium tank, and then you buy a low capacity heater, then you might not be able to achieve the results that you had envisioned in the first place. At the same time, the size of the fish tank will help you understand the number of heaters to buy. If it is big, then you might want to buy more than one heater.

Salty or fresh water?

It is also important to consider the kind of water in which you are rearing the fish. Different water heaters work differently under different conditions. There are those that will work properly even when used in salty water, while others might not work. So as you plan, be sure to first know if your water tank is salty or not, and buy an appropriate aquarium heater.

Cost of the aquarium water heater

Fish tank heaters are priced differently, depending on their unique features and characteristics. For this reason, it is important for you to go for a heater that you can afford. If you just purchase a water heater without considering the cost of purchasing as well as maintenance, then you might find it hard budgeting for other aspects of the fish tank.

And apart from the purchase and maintenance costs, you also need to factor in the cost that will be associated with the power to operate the heater. You can choose to use propane, natural gas or electricity, but then these will not just come for free. You will have to pay. So as you purchase, be sure to factor in the source of the power that will be required to make the aquarium heaters operational.

Ease of installation

While most of the fish tanks are easy to install, there are those that will need some skills when installing them. This necessitates the need to consider how easy it is to install the heater.

The fish species that you are keeping

Not every water heater works for every fish species. While you buy a heater, you will need to keep in mind the kind of fish that you have. Conduct research to find out which fish tank heater is best for your fish species.

What are the various types of aquarium heaters?

In the market today, you will find various types of water heaters. This means that you need to know these types before you visit an aquarium heater store to buy one. Below are the common types of aquarium heaters;

1.      Submersible heater

These types of heaters sit under the water. Usually, it is supposed to be placed at the inlet so that it can heat the incoming water.

The heater is made up of a coiled element which has been encased in a glass of toughened plastic tube. Also, these types of heaters have a LED light placed near them to help you know whether it is on or not. Experts say that this type of heater is better than the immersible one when it comes to keeping the fish tank at a more stable temperature.

2.      In-line aquarium heater

The inline aquarium heater is best when fitted between the sump and filter so that it can heat the water as it comes back to the fish tank. The heater is made of a plastic which is heatproof.

The inline aquarium heater is the best for those fish keepers who have large and aggressive fish that fight with equipment in the fish tank. But it is also important to note that these types of heaters are generally more expensive than any other aquarium heater type.

3.      The filter heater

This is a type of fish tank heater that comes with the filter. The filter is fitted with the heater so that as the water passed through it, it is also heated before it goes back to the tank. You can easily find this type of heaters when you buy either the canister or powder filters.

4.      Immersible aquarium heater

This type of heater is also known as a hanging aquarium heater. The name comes from the fact that the heater hangs over the top of the fish tank and sits in the water. These heaters come as a starter pack for beginners, as they are the most common water heaters for fish tanks.

It only provides basic heating, as it is not as efficient as the other aquarium heater types. They are not recommended for brackish or saltwater setups.

5.      Substrate heater

Honestly, these are not actually aquarium heaters as they are not independent. They come with other types of heaters and are in the form of wires that are then fixed onto the base of an aquarium. They were popularly used in planted tanks as the heating promotes gentle water movement that can stimulate the growth of roots. They are very expensive, thus not often used by fish keepers.

7 best aquarium heaters to buy

1.      Freesea Aquarium Fish Tank Heater

Are you looking for a compact and easy to hide heater? Then this is the best choice you have. The heater comes with an easy to read large LED display. For ease of use, the heater comes with an exterior button which is used for setting the fish tank temperature from between 59 and 94 degrees. You will also appreciate the fact that this aquarium heater comes with a whole 12-month warranty.


  • Easy to hide, thanks to its oval shape
  • Easy installation, thanks to the integrated suction cups.
  • Automatically maintains the set temperatures.
  • Easy to adjust settings using its external button
  • Easy to read the temperatures as it has a large LED display



  • The temperature control box of this type of heater is not waterproof, thus vulnerable.
  • It can only work correctly when submerged, thus cannot be removed from the fish tank.
  • Comes with a short power cord, only 3.5 feet long
  • Can only work best in a fish tank with high water circulation.


2.      Hygger Submersible Fish Tank Heater

This is also a submersible aquarium heater that is both easy to install and easy to maintain water temperatures. As a fish keeper, you actually deserve this, as it is designed to last longer than others, going well over three years.


  • Comes with a long power cord of about 5.4 feet. This makes it easy for it to reach most parts of the fish tank.
  • Has an auto shut off for easy protection from over-heating.
  • Can easily maintain fish tank temperatures at a constant value automatically
  • It has a LED indicator which can let the operator know when it is on or off.
  • It is durable.
  • Its compact design makes it easy to hide it in the aquarium
  • Works for both fresh as well as salty water tanks.
  • It is easy to install as it comes with a detachable shield and two suction cups.



  • Cannot be used in a sump or turtle tank
  • Cannot be placed under the substrate
  • Can only be installed horizontally due to its design.
  • Can only work in glass tanks, not in acrylic or plastic fish tanks