If you are already passionate about aquarists, we are sure you are familiar with the importance of an aquarium water heating system.
But if you’re a beginner, you probably do not really have to choose and buy the right accessories, especially if you do not even know what important parameters to keep in mind.
Many buyers have the cost of purchasing as a criterion of choice, and they are only interested in finding an aquarium heater at good prices.
Others prefer to be thoroughly documented, to make sure they make the right choice, and for the latter, we have prepared this complete guide with objective selection criteria.
Recommended Fish Tank Heaters
- Tetra Ht Submersible Aquarium Heater
- NICREW Submersible Aquarium Heater
- Fluval E 100-Watt Electronic Heater
- Hygger Submersible Aquarium Heater
- Hydor In-Line External Heater
Things to Consider Before Buying a Heater for Your Fish Tank
Installation location: Depending on the place where it is installed, the aquarium heaters can be immersed, submerged, submerged or mounted on the filter.
The immersion model is considered to be the most affordable if it is to look for the best aquarium heaters and the cost of the acquisition. The problem is that the control knob has to be permanently placed above the water level and that setting the right temperature is sometimes difficult.
Considering the low acquisition cost, it is a good solution for a beginner, to purchase a more advanced model, or as a backup solution if the piece you use usually fails.
The submersible model is somewhat more expensive, but it can be placed entirely underwater. The heater positioned in the thickness of the substrate is represented by heating cables; it has a more uniform effect than other functional types and contributes to the pleasant appearance of the aquarium because practically it is unobservable.
It is a suitable solution for those who love natural plants, whose growth is stimulated, but if you encounter a problem, it is necessary to dismantle the whole aquarium to change them, which is not very easy or convenient.
The latest and most modern solution is that of filter heaters that adjusts the water temperature as it is filtered. They are advantageous because they are aesthetically pleasing because there is no need to increase the number of equipment introduced into the aquarium, but buyers may have retention linked to the purchase price that is quite large in this range, as is and expected for a modern gadget.
Heating power: Choose according to a few parameters, the most important of which are the number of degrees with which the water usually needs to be heated and the capacity of the aquarium. Estimate the usual temperature in the room where the aquarium is located and lower it from the optimal water temperature; you will get the number of degrees that water needs to be heated.
Do not hesitate to consult the special tables to make this choice. The estimated rule is that a 25 watts power heats a 5-liter volume of about 20 liters of water. Starting from here, it will be easy to evaluate the power you need on your own.
If the values you get between two models, they opt for the strongest of them. If the aquarium is unusually high or is unusually cold in the room, it is good to buy two devices that you can place in the opposite ends of the container. As a general rule, heaters are available with power ranging from 25W to 300W.
A particular situation is that of mini-heaters: they are suitable, for example, of small bowls with Beta fish. With powers between 7.5 and 15 W, they are submersible and can be placed on the side of the aquarium or on the bottom of the aquarium beneath the gravel.
Material: Traditional, these heaters are made of glass, but the option is not to the liking of the most demanding buyers, because in the case of large, or especially energetic fish, there is a risk that they will break. This is why strong plastic or very thick glass are preferred under certain conditions.
Location: There are plenty of controversies about how the heater should be placed inside the aquarium. Some specialists say the best position is near the filter, where water circulation is more intense, and the temperature will be equalized faster.
Other aquarium specialists will advise you to opt for the variant under the gravel when possible, as hot water currents will climb to the surface, while cold water will come down and heat up in turn.
If your fish enjoys a very generous space and the container has a capacity of over 150 liters, maximum efficiency will be achieved by placing two heaters in the aquarium’s side areas. Other aquarists prefer to opt for two small capacity heaters, instead of a large one, even for slightly smaller spaces.
Maintenance and cleaning: Although modern aquariums no longer need to be cleaned as often as they once were, workmanship should still be done periodically. Therefore, to reduce effort and time, we advise you to choose an easy-to-clean model that requires minimal maintenance.
Other Features: If you have extremely precious or very sensitive fish, it is advisable to purchase a top-quality heater that includes additional functions: thermometer and/or thermostat. If they are digitally controlled, we are already talking about a professional attitude that you can trust with confidence.
Price: Contrary to the general opinion, the aquarium is not a very cheap hobby. So it’s not a bad idea to find out where to find an aquarium heater at a good price for other buyers.
List of Best Aquarium Heaters
Most of the time online stores have advantageous deals for the same products as those found in specialized physical stores. In addition, their offer is much more varied and accessible from the comfort of your home, just a few clicks away.
1. Tetra Ht Submersible Aquarium Heater With Electronic Thermostat
The Tetra HT Submersible Aquarium Heater with an electronic thermostat is easily one of the most popular aquarium heaters on the market. This heater can accommodate tanks up to 30 gallons, available in 50w and 100w sizes. This Aquarium Heater for small aquariums is completely water-resistant and perfectly sized. It can also be installed vertically or horizontally so that you can put it anywhere.
The Electronic Thermostat Tetra HT Submersible Aquarium Heater features an inbuilt electronic thermostat which automatically maintains a temperature of 78 ° F, ideal for most tropical fish. The heater also has an indicator light that allows you to know when activated–when the desired temperature is reached green and when heated red.
2. NICREW Submersible Aquarium heater
This completely submerged heater has a sleek and slender design that fits into stylish homes, and a touch control system. The heater is equipped with an LED that shows both the heater temperature and the tank temperature. You can adjust the temperature to 96 ° F from 66 ° F.
The thermal circuit is integrated and shuts down the heater before it can overheat, and it is made from a scratchproof outside case that makes the heater virtually non-destructible. Depending on your tank’s sized and heating requirements, it comes in a range of sizes from 25 watts to 250 watts.
3. Fluval E 100-Watt Electronic Heater
The Fluval E series of heaters are equipped with a Celsius or Fahrenheit temperature display. They are fully immersed and are equipped with an alarm to change the color of the LED so that the temperature changes after the preset temperature.
The heater comes with a built-in fish guard that protects your fish against heat. These heaters come in a variety of wattages that are suitable for a wide range of tank sizes.
4. Hygger Submersible Aquarium Heater
In this heater line from Hydor, the Original Theo is the smallest. The control button is marked with increments of one degree and can be set precisely after certain modifications. The heater body length is short enough for tanks of 2.5 gallons to accommodate. Its body is shatter resistant and shock-resistant, and the light indicator lets users know when the heater is in operation.
This heater can be installed in the fish tank horizontally or vertically. The length of seven inches is ideal for tanks with a size of fewer than 10 gallons. It is not as sensitive for smaller tanks as it can be for the integrated thermometer. The control button is sensitive and can be corrected with several adjustments.
5. Hydor In-Line External Heater – Original ETH
The filter is an external, tropical as well as marine thermal heater. It can be used only vertically, however, and connecting and using is easy. It was designed for the return line from canister filters or buckets, returning to the tank and heating the water on the way back.
The positive thermal coefficient (PTC) technology ensures self-heating and blowing. It comes with piping between 12mm-16 mm and it has temperature control for easy vision, depending on the size you want.
6. Cobalt Aquatics Neo-Therm Aquarium Heater
You can set the temperature range between 66F and 96F and keep the water temperature within 0,5F depending on Cobalt. The heater has a modern, super flat design, which does not remove your tank beauty.
Easy to access, the “one-touch” control system displays both the set temperature and the current tank temperature with LEDs.The heater is completely submerged and shatterproof, so there are no cracked glass concerns.
7. Eheim Jager Aquarium Thermostat Heater
Because of the size, it may need to be placed in your tank horizontally. If this is placed vertically, the length can be a major bonus, since the dial is very close to the aquarium area–making it easy to set the thermostat without endless squabbles.
The TruTemp dial has an easy, easy setting function that enables you to set the temperature you want; keep the temperature at 0.5F. However, you will have to repeat the calibration procedure a few days after the initial configuration. The handy light on / off makes it easy to monitor whether or not the heater works.
8. Hydor Submersible Glass Aquarium Heater – Original Theo
An inexpensive and good aquarium heater that we propose is the Hydor model. Its efficiency is due to patented PTC technology – positive thermal coefficient – which makes its use perfectly safe. The heating is achieved by means of a specially coated element on which a graphite ink layer is applied.
Because the temperature does not exceed 80 degrees Celsius, the element is also protected from thermal shocks, which can occur in the case of electric resistance heaters.
The 300 W power makes it suitable for aquariums up to 200-300 liters; for larger capacities, you can purchase two such products, as the integrated thermostat will take care to maintain the water temperature at optimum values and to minimize power consumption. In addition, the built-in thermostat makes it extremely precise in temperature adjustment. Made from incapable glass, the product is also appreciated by chia and by experienced enthusiasts.
9. Aqueon Pro Heaters Submersible Aquarium Heaters
The Aquarium Heater is a state-of-the-art aquarium heater, accurately equipped with a 1-grade electronic thermostat, with a wide temperature range from 68 ° F to 88 ° F. This aquarium heater has a shatterproof construction and is completely submersible for durability. Place the heater in the tank near the filter outlet for even heat distribution for best results.
In addition to being very precise and adjustable within 1 degree, the Aqueon Pro Adjustable Aquarium Heater provides several security features. It is automatically stopped to protect against overheating and resets when it cools down automatically. The red LED activates the heater when the water temperature falls below the desired setting, and the light turns green if the temperature reaches the desired level.
10. SZELAM 25W Smart Mini Aquarium Heater, Betta Fish Tank Heater
A small heater that is suitable for small tanks and betta tanks. It can be efficient in tanks up to 6 gallons due to its 25W power. It has a thermostat that automatically switches on and off when the temperature reaches its optimal range.
On the bad side, many units tend to fail after some time of use making it not that very reliable, that is why it landed on our last spot of the list.
Practical Tips for Using an Aquarium Heater
When replacing the water, remove the heater from the socket at least 10 minutes before. Warm glass cracks gently when subjected to high fluctuations in temperature. In addition, there is a risk of burning your hand. In the same way, never insert a heated or connected appliance into the cold water.
Place the internal heaters in the vicinity of the filters or pumps. Currents provide better circulation of heated water inside the aquarium.
Also, install an aquarium thermometer for temperature overheating. The heater thermostat may fail or cause errors, and then you will have an arc in the sleeve to check the temperature.
Fix the internal heaters with suction cups. Most come with these accessories, but if it is not, buy some extras. Unfixed heaters can hit the walls and break.
Place the fully submersible heater on the bottom of the aquarium in a horizontal position so that warm water rises to the surface and heats up the whole water column.
More on the types of aquarium heaters, very important to know.
There is a category of submersible heaters that do not have a thermostat, so you need a thermometer indicating the temperature in the aquarium and much attention to turn off the heater when the water has reached the desired temperature. The price difference between them and the above does not amortize the effort and the risks.
Substrate heaters: They are very old on the market, but they do not enjoy too much success. As the name says, put them on the bottom of the aquarium under sand and/or gravel and heat the aquarium efficiently from the bottom up with convection currents.
Another great advantage is that it ensures a higher temperature in the substrate, which does not happen to the other types of heaters, favoring plant development.
They do not have a thermostat, so they’re harder to control. In addition, if they have not been placed since the start of the setup, nothing can be done.
External heaters: They are more expensive than the above but more accurate and efficient. They can be either in-line or directly attached to the filter system.
The big advantage is that it does not occupy space in the aquarium and there is no risk that the fish will burn or damage (some cyclists attack the aquarium installations). The in-line is attached to the aquarium water return through a tube system. How extra piping attaches increases the risk of leakage or flooding.
Filtering systems with heater are excellent, practical, loyal, but very expensive. When water passes through the filter it is also heated. With a thermostat, the temperature can be adjusted.
It is a compact, easy-to-use system. Heated water returns directly into the aquarium, and with the pumping system, it is rapidly mixed with the existing water. A negative aspect is that if the heater or filter fails, the whole system needs to be changed.
DIY Aquarium Heater – Is it worth it?
When making such a device, you must remember that its operating conditions are associated with a serious electric shock hazard.
But if the decision was taken in favor of artisanal crafts, then there is a good option by creating a resistor construction, a piece of the thick wall glass tube, a dry filler, and an external thermostat. Installation work is done in the following order.
The power of the heating element is determined on the basis of a special table, which takes into account the temperature difference between the required requirements in the aquarium and in the room. The required resistance of the current is calculated by dividing the selected power at the applied voltage.
By dividing the voltage used by the calculated value of the current, you can obtain the resistance value of the heater. The required number of identical resistors is selected so that the total power and resistance index corresponds to the calculated values.
- Determine the length and diameter of the glass tube according to the size and number of resistances.
- It is important that successive glued resistors are placed in the tube with a spare 15 cm of free space.
- In the filling role, you can use calcined sand.
- The bottom of the glass tube is closed with a suitable rubber stopper mounted on the aquarium sealant.
- The ends of the mains cable are glued to the top and bottom resistors. The entire structure is placed in the tube and covered with sand. It is important that the sand is on the bottom of the tube and cover the upper strength.
- The end of the tube is carefully closed with aquarium sealants. The power cable is connected to the thermostat with a remote temperature sensor, which in turn is located in the aquarium.
- The heater is placed vertically. so that the part of the tube in which the resistances are located is hidden underwater. The design mounted on the aquarium wall with special suction cups.
How many watts does my aquarium heater need to be?
Depending on the size of the tank, aquarium heaters can range from 5W up to 500W. If you have a small tank, such as a betta tank or something up to 10 gallons, a 30W heater will do the job right.
But putting a 30W heater in a bigger tank, it’s not that efficient since the water will only heat up near the heater and not in the other places of the tank. For bigger tanks, it is recommended that you get a heater with a bigger power range, such as a 100W or 200W one.
Keep in mind that there are aquarium heaters that allow you to switch the power range, they are a bit expensive but they tend to be more versatile and can be swapped from one tank to another.
|Tank Size||5 Degrees C
9 Degrees F
|10 Degrees C
18 Degrees F
|15 Degrees C
27 Degrees F
|5 Gallon/25 Liter||25 watt||50 watt||75 watt|
|10 Gallon/50 Liter||50 watt||75 watt||75 watt|
|20 Gallon/75 Liter||50 watt||75 watt||150 watt|
|25 Gallon/100 Liter||75 watt||100 watt||200 watt|
|40 Gallon/150 Liter||100 watt||150 watt||300 watt|
|50 Gallon/200 Liter||150 watt||200 watt||two 200 watt|
|65 Gallon/250 Liter||200 watt||250 watt||two 250 watt|
|75 Gallon/300 Liter||250 watt||300 watt||two 300 watt|
What kind of fish need a heater?
All types of aquarium fish require the water to be above 35 Degrees F. It is important to keep the water warm for them so they can enjoy it. Keeping fish in cold water will make them lose their will to live, they will become lethargic and eventually, they will die.
On the other hand, keeping fish in hot water will have the same effects on them. Having an optimal temperature range is important.
You can refer to your fish data chart to learn more about their optimal temperature range.
How much do fish tank heaters cost?
Aquarium heaters price is fluctuating depending on the features and build quality of the heating unit, as well as the brand.
While in most cases, having a product from a known and well-established brand can be a good choice because of the excellent build quality and warranty period they offer, some cheaper brands can work just fine, especially if you are on a tight budget.
You need to stay away from dodgy looking heating units, these tend to have a very bad build quality and they will break quickly and most importantly you can get injured or even worse when handling an improperly built aquarium heater.
Where should I place the heater in my fish tank?
Depending on the type of heater you are using. Most heaters are made so that they can be placed on the aquarium wall.
A good practice is to place the aquarium heater near the water filter or the skimmer so that the water that gets heated can be dispersed through the aquarium and having it all get to an optimal temperature.
Can you put two heaters in a fish tank?
Yes. This is a common practice among aquarists who own large aquariums. Placing 2 heaters on the opposite sides of the tank will make the water heat up faster and will cover most water from the tank.
But keep in mind, don’t place the heaters very close to one another since their thermostats will go nuts and the efficiency will be reduced.