Types of aquarium heaters
There are several types of heaters for sale, which can be adapted to different situations and obviously to different budgets.
Internal aquarium heater
The internal aquarium heaters are obviously placed inside the aquarium.
They are usually made of glass, but there are also models made of other materials, such as titanium or steel.
They have a heating element inside, which takes the temperature to heat the water in the aquarium.
They are usually thermo-heaters, so they have an internal thermostat installed to start or stop them, depending on the temperature at which we have programmed them.
There are two types of internal aquarium heaters:
Clamp or hanging thermostats
The hanging or clip-on heaters are made of glass and as a peculiarity, the top has to be above water, they are not completely submerged.
Their popularity is justified by their price, they are probably the cheapest heaters.
Submersible heaters
Among the fans with a slightly bigger budget, they are the most used.
These are heaters that can be completely immersed in the aquarium.
As they are completely submersible, they allow us to choose where we want to place them, varying even their inclination, so that we can place them in the least visible part of the aquarium.
They are very flexible and safe, although we must be careful not to place them directly on the substrate.
External or filter
These heaters are placed in the aquarium filter, so that at the same time as the filtering process takes place, the water on return to the aquarium reaches the appropriate temperature.
The advantage is that there are no accessories in the aquarium that can be visually “ugly”, although as a disadvantage they are not very effective, and the aquarium may not be at the right temperature at all points.
It is also possible that it is not compatible with your current filter, so if you decide to use this type of heater check first that you can use it.
Heater cable or bottom heater
Heating cables can be used in aquariums without any problem, indeed, they can be advantageous in a planted aquarium, as the heat will reach the roots of the plants very directly and we will see spectacular growth.
Their main disadvantage is that they are difficult to assemble and must be done before the entire aquarium is set up, since they are placed under the substrate. In addition, some do not have a thermostat. In these cases, a thermostat must be fitted to control the temperature of the aquarium, and to mark when it is switched on and off. The main advantage of this is that there is no appliance in sight and, if desired, since we have installed an auxiliary thermostat, we can install a system to cool the aquarium.
I think this may be the best option for heating the aquarium, but it is reserved for more experienced hobbyists.
Where should the heater be placed inside the aquarium?
You may have doubts about where to place the aquarium heater. The final location will depend on aesthetic considerations, although technical aspects must also be taken into account.
Experts advise that the heater be placed:
- Close to the water filter inlet, as the warm water will be sucked in together with the colder water that is usually at the bottom of the aquarium.
- Other experts recommend using a submersible filter, placed horizontally near the filter outlet.
- It is also recommended to place an aerator under the water heater (if it is submerged), so that the cold water of the aquarium, usually on the bottom, is pushed towards the warmer part of the aquarium.
My own advice is to place the aquarium heater close to the bottom, where the water is much more dense as it is colder. In this way we get the cold water to warm up, to rise to the surface and as it cools down again, it is heated by the effect of the heater and the process is repeated. I think that this way we get a much more uniform temperature inside the aquarium.
Tips for choosing the right aquarium heater
Once you are clear about the different types of heaters available, you may already have a pretty good idea of which one you like best. But we haven’t finished yet, because not all heaters are the same. As with aquarium filters, size does matter…your aquarium.
Every aquarium heater is designed to heat a certain number of liters, so we have to buy the right heater for the liters in our aquarium. If we choose a very small heater, it may not heat the aquarium well, or if it does, it is working beyond its capabilities and lasts less time. However, if you choose a heater that is too large, it can heat up the aquarium water too quickly, which can damage the fish.
There is a trick to determine which heater is the most suitable, and is to look at the wattage, and associate 1 watt to 1 liter, so a 60-watt heater is suitable for a 60-liter aquarium. If we have to raise the room temperature of the water a lot, it is advisable to choose a heater with more power.