Table of Contents
What is the right temperature in an aquarium?
Let's start with the water temperature, which is required. Here you can not give a general recommendation, but must be based on the profiles of the fish. Each species of fish has a specific habitat. Be it in the Amazon, in South America or in the area around Thailand. Even in our latitudes there is a certain temperature range.
Since fish are not warm-blooded, but cold-blooded animals, they adapt to the environmental conditions. Compared to humans, they do not always have the same body temperature. Therefore, it is important for us aquarists to adapt the temperature to the fish and the natural habitat as precisely as possible. A fluctuation of two degrees is not a problem, but you should be careful when the temperatures are too cold. Here the fish are quickly stressed. If the temperatures are too high, the service life will be affected. Well-tempered aquariums usually have the advantage that they represent a better habitat than in nature. Many of the world's major fish kills occur due to severe cold spells.
Because of this mnemonic, you should also make sure in community tanks that you only keep fish with the same requirements in terms of temperature and other water parameters.
Which heating or heating systems are there?
Let's now look at the various ways of bringing the aquarium water up to temperature. There are various devices for this purpose, which we will now present.
Heating rod, adjustable heater or rod heater
Probably the simplest and also the most common way to heat up your water is to use a heating rod. This is often also called a control heater or rod heater. The structure is basically in two parts. The bottom part of the glass tube is the resistor and the ceramic part that provides the heating. In the upper part is the regulator, which regulates the voltage supply of the heating element with the help of a bimetal. You can set the temperature on the top. The bar heater usually hangs on the side or behind on the inside of the aquarium with suction cups. This means that there is also a live part in the water, which is why there are a few things to consider when it comes to safety.
These control heaters have been in use since the beginning of aquaristics. In the past, the controller and the actual heating element were separate from each other. Today this is always integrated in one device. The bar heaters are available in small watt numbers such as 25 watts up to 500 watts. We explain which power you need for which pool further down in the article.
When using the rod heater, you should definitely observe the manufacturer's instructions Manuals and the Safety rules. When working in the aquarium, always de-energize and de-energize the devices.
Finally, a word about the cost of the adjustable heater. This is certainly the cheapest way, especially in terms of acquisition costs. Here the models start at 10 euros. One of the best-known manufacturers is Jäger, but Tetra and Sera also have these heating systems in their range.
Advantages and disadvantages of a heating rod, adjustable heater or rod heater
Benefits
- inexpensive purchase
- fast assembly
- up to 500 watts available
- failure safe
Disadvantages
- Sensitive to shocks
- very hot surface
- poor distribution of heat in the pool
- Live device in the aquarium
Heating in the filter – thermal filter
Basically, this type of heating is similar to that of the rod heater. The difference lies in the placement. With the thermal filter you have a device that is located in the base cabinet and takes over the heating as well as the filtering. So you don't need to hang a device directly in the aquarium. This type of heating is usually more expensive to buy but still has a certain charm.
Advantages and disadvantages Heating in the filter – thermal filter
Benefits
- Good heat distribution
- Placement outside the aquarium
- failure safe
- No live device in the aquarium
Disadvantages
- More expensive than bar heaters
- Heavy exchange
Floor washer, floor heating cable or floor heating or heating mat
Another form of heating is the floor washer, floor heating cable or floor heating. A heating cable is laid at the bottom of the aquarium, under the culture medium and gravel, which heats the bottom from below and thus also the aquarium water. The performance of this system is usually not sufficient to achieve the desired values. So this only serves as a additional heating has a decisive advantage, especially when it comes to plant growth. Plants love warmth from below. We therefore recommend installing this type as additional heating. However, this must already be installed during setup. This is difficult to do afterwards. Another disadvantage is also the regulation. Here you usually need dual controllers, which can control two heating systems separately. But more on that later.
Advantages and disadvantages of floor washlights, floor heating cables or floor heating
Benefits
- Very good plant growth
- Even distribution of heat
- Easy installation for new setup
Disadvantages
- Expensive purchase
- Not sufficient for sole heating
- Mostly not continuous operation
- Further regulations necessary
- Difficult to install afterwards
Special form of outdoor floor heating
The outdoor floor heating is certainly a special form. This is used very little today, as it has a major disadvantage, especially in terms of consumption costs. But first a word about the structure. Basically, one can speak of a bottom floodlight here, except that it is placed outside of the aquarium. These heating plates are pushed under the aquarium and thus indirectly heat the tank. Since glass is not exactly optimal when it comes to heat conduction, a lot of energy is required here. This is why this heating system is hardly ever used today.
Advantages and disadvantages outdoor underfloor heating heating plate
Benefits
- Easy construction
- No electrical devices in the aquarium
Disadvantages
- High consumption costs
- High acquisition costs
- Lots of energy needs
The decision question
It is not always easy to decide on a single heating system and it certainly depends on a number of factors. In addition to the size of the aquarium, the desired stock also plays a major role. It depends on what temperature is ultimately required. Whether you attach great importance to the plants in the tank can also be decisive. The environmental conditions at the installation site are also an important factor in selecting the appropriate heating system. The necessary power is calculated accordingly.
Ask yourself the following questions:
- How big is the aquarium?
- What temperature is required?
- Are there plants?
- What is the ambient condition in the room like?
- What is your budget?
What regulations / controls are there for heating?
Here, too, the manufacturers are now offering a lot of high-tech. Be it fully automatic computer-controlled regulations, which can not only control the heating, but also the lighting and even the Co2 enrichment in an automatic system. There are also individual regulations for heating control. Here, the devices are named by Dennerle Duo Control, for example. The functions are quite varied here. Be it the automatic control of the floor floodlight and the adjustable heater in a certain dependency, or the night-time reduction of the temperature can be realized with it. The whole thing is then implemented via a temperature sensor and the controls installed in the devices are no longer influenced.
Many controls even have the option of switching between heating and cooling. Of course, the corresponding cooling device is also required for this.
Whether you need a regulator or separate regulation and control ultimately depends on the heating systems used. In addition, the demands of the fish must also be considered here.
Especially in breeding, it can be necessary to simulate different temperature ranges and fluctuations in order to get the fish ready to mate. Devices with cycle control and reductions are recommended here. Certainly not suitable for beginners in aquaristics.
Install additional measuring and control systems – thermometers
A very important device is the temperature control system. The ones built into the control heater are usually very imprecise. Therefore, additional control instruments must be installed here. Today, this includes above all digital temperature gauges. Thermometer to measure the water temperature very precisely. These are usually placed outside and have a probe that is placed inside the aquarium.
We advise against using the mercury thermometer today. These have great disadvantages or dangers for the fish, especially if they are defective. In addition, the response time is quite short. The advantage is of course the reliability. With a digital thermostat, the battery can sometimes be empty.
Nevertheless, you should definitely buy this as a fallback and for comparison.
Even better are thermometers with an alarm function. It could also be that the heating is defective and if you do not check the temperature regularly (almost daily !!), then the fish can be in great danger. So you'd better spend a little more money here.
How much does an aquarium heater cost?
Let's take another look at the price. The most economical way is certainly to use the conventional adjustable heater. These are already available from 10 euros and increase in price according to the output in watts of the heater. The devices that are installed in a filter are more expensive. So-called thermal filters do cost a lot, but have their advantages as described above. You should consider this approach, especially when purchasing a new one.
Underfloor heating or floor floodlights are also not exactly cheap. Here, of course, the length of the heating cable and the wattage are very important. In addition, a controller is then required, which can quickly cost 100 euros or more.
Above all, the combination of adjustable heater and floor washer will tear a decent hole in the petty cash, but this variant is probably the best. We recommend spending a little more money and gradually increasing the stocking. After all, you don't have to have all the fish in the tank right at the start. However, the technology should fit.
How strong should the heating be? How many watts do I need for the heating controller? – benchmark
This question is also not easy to answer because, as we have already learned, this also depends on various factors. Nevertheless, there is a guide value, which also fits very well. You have to distinguish whether the pool is in a well-heated room or in a rather unheated room. Depending on the ambient temperature, less or more power is required.
The heater should be designed larger rather than smaller in order to have any reserves. For example, you are on vacation and lower the room temperature. In this case, the aquarium heater has to do a lot more.
How much power in watts do I need for my aquarium?
This is not easy to determine because it varies greatly depending on the room temperature and the desired temperature in the pool. Here you can also speak of the target and actual temperature.
There are a number of tables in the specialist literature that give you a quick overview of the required power depending on the required temperature for the room temperature. Basically, it's about the difference in how many degrees the water should be heated. It all depends on the water volume.
The manufacturers always indicate the approximate amount of liters in the aquarium for which the heater is suitable on their devices. These fit quite well at a normal room temperature.
There are also a lot of empirical values that will help you here. In addition, there are also special formulas that can calculate exactly this. However, these are always based on a certain proportionality factor, which should be found out experimentally. However, we have a formula that roughly illustrates this.
What is needed for the calculation?
- Room temperature eg 20 degrees
- Necessary water temperature eg 25 degrees
- Heating temperature difference eg 5 degrees
- Surface of the aquarium on all sides
For example:
T1= 20 degrees room temperature
T2= 25 degrees aquarium water target
A = Aquarium area = 1m x 0,5m = 0,5 an area times this by 4 gives 2 + (0,5 x 0,5) x 2 = 0,5 = 2,5
Proportionality factor assumed to be 8 (proven in practice)
Calculation tool for aquarium temperature calculation in watts and power
If you compare this value with the rule of thumb of 0,5 / 1 watt x per liter, you are at 100 - 200 watts. Since there is no 130 watt heating controller anyway, you should always round up and a 150 watt heating controller would be required. So the result is roughly correct.
This formula gives you a lot of reserves. You can also use an efficiency of 7 in a warm room like the living room.
Of course, there are other formulas on the Internet that do not refer to the surface of the aquarium, but to the water content in liters. But a proportional factor must also be assumed there. Unfortunately, to our knowledge, there is no physically correct calculation with a fixed formula.
Power consumption of an aquarium heater?
Depending on which watts of power you have calculated and used above, the power consumption will also be. Of course, the heating element does not always run continuously. Normal operation is about 1 to 2 hours a day. This means that the heating costs are also manageable.
For example:
100 watts times 2 hours per day x 365 = 73.000 watts or 73 kw/h times 0.30 cents per kw/h = 21,9 euros a year
All consumption cost calculations can be found here:
Calculate maintenance costs of an aquarium
What is the durability of a heater in water?
Heating controllers can usually be used for many years. There are few flaws here as far as our experience goes. Also with them This is the case with floor washes.
What do you have to consider when maintaining heating systems?
There is basically little to pay attention to here, apart from external cleaning from time to time. Here you should be careful not to damage the heater control. If the glass bulb is damaged, the heater must be replaced.
When installing, it is important to follow the operating instructions exactly. Above all, the immersion depth must be observed here.
Be prepared for emergencies
One thing you should always keep in mind. If the heating fails, a replacement must be found quickly. That's why we always recommend having an emergency heater in the house. This means you can react quickly if something should go wrong. And the whole thing is not expensive either.
You can also hang a second and additional heater in the pool in addition to the actual heater, but set the temperature to a much lower level. This switches on when the actual control heater fails. Of course, the target temperature would then not have been reached, but it would be better than further cooling and thus the certain death of the fish.
Of course, as already recommended above, one is better Thermometer with an alarm function. These are already available for cheap money.
Any questions?