Internal filters or, as they are also called, submersible ones, due to their specific nature, devices and structures have several advantages over external filters for aquariums. Installation of such filters does not require additional space around the aquarium, since all communications (hoses, drain pipes) of the filter are located together with the filter in the aquarium. This makes them easier to maintain and clean.
According to the specifics of their structure, all internal filters are similar to each other. The structure is very simple: it is a pump that is responsible for the water supply and the tank where the filter element is located. As you can see, everything is very simple and in the case of an ordinary breakdown, such as weak suction of water or poor filtration, any aquarist can cope with it. To do this, you just need to disassemble the filter, replace the filter element, flush the container and tubes from possible debris particles. There is one drawback to the internal filters with an air compressor: it is a weak power and, due to this, low cleaning intensity. Therefore, highly contaminated water in an aquarium with such a filter will be difficult to clean. But, if necessary, carbon filters can be inserted into such filters for more thorough cleaning.
Despite its simplicity, these filters rightfully occupy a leading position among aquarists. First, they win the pricing policy for more complex filters for chemical and biological cleaning. Most aquarists prefer internal filters, but at the expense of cheapness they forget that they are intended primarily for mechanical cleaning. Do not forget that the environment of the aquarium needs both chemical and biological treatment. Also, a slight drawback of the internal filters is that by immersing it in water, you will need to somehow mask the tubes that are suitable for it in order not to spoil the decor of the aquarium. Such filters are used in containers up to 180 liters. Despite the statements of manufacturers of such filters, which are written on the package (200 and over liters), this is the limit of the capabilities of the filters in this category.
The main functions of the internal filter:
– mechanical water purification
– chemical cleaning (with the replacement of the usual filter element on coal)
– biological treatment (with the replacement of the filter element on the corresponding)
– circulation of water in the aquarium
– soil aeration
In accordance with the emerging need, each aquarist chooses what function the filter will perform. So, for an aquarium where cichlids prevail, such filters are used for soil aeration. Also internal filters are used in those aquariums that perform the functions of quarantine and jigging of fry and sick fish.
Internal filters have more decent forms than head filters, as well as low noise performance, which is more acceptable for room aquariums. Also, many internal filters are used to pump water from the aquarium. To do this, you simply need to put on a hose of the desired length on the outlet pipe, and water is pumped without using a bucket or other containers.
As described earlier, all internal filters have approximately the same device. In most cases, they are a plastic box, which consists of two parts. The lower part is usually hollow or may consist of several prefabricated parts, the so-called compartments, intended for the location of filter elements in them. The bottom part is the carrier of the filter element. For uniform washing with water of the entire area, holes are provided in this part, and a tube inside. These filters are attached using special suction cups located on the filter housing on the inside of the aquarium, while completely immersed in water. By law, the best filter element is foam rubber. Because of its structure, foam rubber includes cavities in which in the process of work useful bacteria can live and reproduce. It is worth to use special waterproof foam rubber, otherwise ordinary foam rubber decomposes and crumbles under the influence of water and can get into the total weight of the aquarium water along with the filtered water. The use of fine porous foam is worse, as the pores quickly become clogged, and water purification becomes longer and worse in quality. This leads to the fact that it is necessary to change the filter element much more often. In some models of such filters there is a special compartment for bulk filter media.
Chemical water treatment usually involves treating water with activated carbon or other special chemical elements. How often it is carried out depends on the owner of the aquarium. In the case of fish disease, medications are added to the aquarium environment, which, after a course of treatment, simply need to be removed and nothing better will cope with this task than activated carbon. Therefore, when buying a filter, it is worth considering this factor and acquiring a filter in which there are additional compartments for filling with activated carbon.
The upper part of the filter is a pump that is responsible for pumping water through the filter element. Usually it is a conventional electric motor, the stator of which is hidden in a sealed waterproof case, and the rotor is made together with the impeller, due to which the water is pumped in the aquarium. The overall performance of the internal filter depends on the dimensions and power of the electric motor and can be within 100l / h to 300l / h. During the operation of the filter, water is circulated, due to which the water is mixed and saturated with oxygen. Water flow can be directed in different directions. Usually, the jet of water that the filter ejects is directed along the wall of the aquarium and, due to this principle, a circular motion of water is created in the aquarium. Pure water pushes all the mass and particles of sludge, debris gets into the filter with a portion of water. There again passes the treatment of water using a filter element and is thrown into the aquarium. The pressure of the water emitted by the filter must be such that the water reflected from the wall of the aquarium does not reflect again and does not carry dirt and debris from the filter into the total mass.
Some internal filters have additional functions and devices designed for more convenient and efficient use of filters:
– air tube (designed to supply air to the filter). Thus, during the filtration process, water will be additionally enriched with oxygen. The main mistake that aquarists make when using such a function in closed aquariums is to leave the air tube under the aquarium cover and the water is enriched with the same air, which already has carbon dioxide and little oxygen in its composition.
– output tube with rotation mode (to direct water in the right direction)
– nozzle output tube (for the direction of water flow up or down). When the direction of water flow downwards improves the saturation of water with oxygen, and the upward direction will create fluctuations in the water surface.
– power control (to regulate the flow of water ejected and filter operation)
– direction switch (for directing water in the reverse direction)
– water flow power sensor
– built-in heating element
Despite the relatively low productivity and design inconvenience, internal filters occupy one of the first places on the filter market. For small aquariums, it would be illogical to use a large external filter. In the so-called aquarium picture, put some other filter will not work. When using internal filters in sprinklers and quarantines, it is important that beneficial bacteria can live and multiply in the filtering element of the filter. The population of the aquarium beneficial bacteria favorably, as they play the role of a natural biological filter. Using internal filters for aeration is a very common method. Oxygen from the surrounding atmosphere through pipes and a pump enters the aquarium through the filter, thereby saturating the water.
The performance of the internal filter as a whole depends on the performance of the pump, which is measured in l / h. Also, the performance of the filter depends on the ratio of performance and density of the filter element. If the filtering element is too tight and the flowability is not high, the filter can be slowed down.
Which filter is better, is decided solely by the owners, who proceed from their individual needs of their aquarium. Before you buy a filter, do not forget to think over and take into account all the little things that your pets would feel comfortable in the aquarium.