External Filters versus Internal Filters

 Basically, external and internal filters operate on the same principle. First of all, you should know that there are biological filters, which force the water into the aquarium using a pump system with a foam mat. This foam mat is filled with bacteria that absorb the suspended matter and pollutants from the water, as well as any harmless substances.

Filters 

 

A filter can be installed upstream for larger airborne particles. Similarly, activated carbon can be installed downstream. There are also other aquarium water filters that help to purify the water physically or chemically or that maintain a particular water quality. The filter system can be simple or complex, depending on the requirements of the inhabitants of the aquarium.


A basic distinction is made between internal and external filters. The internal filter is located inside the aquarium and is usually found in smaller aquariums. Larger tanks require larger filters, which are placed outside the aquarium in order for the space inside the aquarium to be used for its actual purpose.

The internal filter circulates the water within the aquarium. It is usually easier and barely audible since it is underwater. There are open mat filters, which are suitable for the removal of suspended matter and pollutants.

The mat can be colonized with specific ferns or mosses, which hinder the cleaning process, but get rid of the optical impediments. If the filter is located in a separate case - possibly together with the pump, it is usually mounted on the rear panel and integrated in the decor so as not to disturb the design of the aquarium. Such a filter can also be accompanied by additional filter media.

Internal filters can also be integrated in larger aquariums, but this is not usually the case. That is what external filters are for. These filters are usually placed next to the tank. Going back to the internal filters, the water is usually taken near the ground, fed by a tube of the pump and forced through the filter. A second tube delivers the clean water back into the aquarium.

Currents can form in the aquarium depending on the strength of the pump, which can be adjusted. This may be required by the stocking. But they are usually weak and close to the surface, so that they do not stir the sand and other particles.

An external filter for proper aquarium filtration can be used for several tanks if the water quality is identical. Those who wish to devote themselves to breeding animals should let them grow up in a separate aquarium. The young fish can easily become the victim of other fish who cannot miss this supplement to their diet.
The external filter pump is very quiet, yet the sound may be audible as it is not attenuated by the water as it happens with the internal filter. You can also accommodate more complex filter systems as an external filter does not occupy too much space. Peat pellets can affect the pH of the water in addition to biological filtration.
A filter must be maintained more or less often, depending on the filter medium. A replacement of the filter media may also be required in addition to the rough cleaning.