Filters for aquariums

The aquarium is a closed environment that is why it is essential to filter its water to ensure a perfect balance and good water quality. There are many filtration systems that can be adapted to your aquarium.

The installation of the filtration system can be done internally or externally to the aquarium. The filtration can be natural, vegetable, chemical or mechanical. It is necessary to choose its installation according to your aquarium and the species that will be raised in it.

What are aquarium filters for?

Aquarium filters are used to eliminate and transform the organic waste rejected by fish and aquatic plants. The main action is filtration. The filters work in conjunction with a pump that is used to create water currents and thus promote the well-being of the fish. By installing a filtration system adapted to the aquarium, the user will change the water less often while providing good living conditions for his fish breeding. An aquarium without a filter would become dirty very quickly and the water would have to be changed every day, which would be very demanding.

An aquarium requires a two-stage filtration:
The ideal filtration is both mechanical and biological. They are generally both carried out by the same filter and allow an optimal filtration. The mechanical filter destroys all waste in the water that is visible to the naked eye. While the biological filter works on invisible pollution. There are also specific filters that remove only invisible pollution.

There are 3 types of filter media for freshwater aquariums:

Mechanical filtration:

retains the debris suspended in the aquarium water thanks to a successive layer of several materials of different sizes. Perlon, synthetic foams, ceramics of various sizes and gravel are used as materials. The layers of materials should be placed in layers from the largest to the smallest. The debris retained by these materials will then pass through the filtration system. This type of filtration requires periodic and regular maintenance and monitoring to prevent the filtration system from clogging and degrading water quality.

Biological filtration :

is a natural method called nitrification. The aquarium must be of sufficient surface area and have a good supply of oxygen. The goal is to provide a large colonization space for the nitrifying bacteria. The materials needed for this type of filtration are gravel, crushed sandstone, crushed lava stone, ceramic noodles and many others. This is the filtration to be favoured in an aquarium for less maintenance since you will only need to occasionally rinse the substrate and change the mechanical filtration foams to maintain efficient filtration. During the first installation of the biological filtration method it will take a few days for the bacterial colony to develop properly. Several types of filtration are used in parallel with biological filtration. Usually it is combined with mechanical filtration, sometimes even with both mechanical and chemical filtration. This choice is made by the user according to his aquarium, his fish breeding and his preferences.

Chemical filtration :

consists of filtering materials that have the property of capturing and absorbing impure elements dissolved in the water. Carbon, resins and other chemicals are generally used as materials. This type of filtration is not a method to be used regularly. For example, carbon will absorb undesirable elements but also beneficial elements such as fertilizers for aquatic plants. The effectiveness of chemical filtration is short-lived and the materials will need to be changed often to prevent the absorbed products from being released back into the aquarium. However, chemical filtration can correct an imbalance in the aquarium quickly and punctually. For example, if you administer a medication in the aquarium water, the use of charcoal for the next 2 to 3 days will remove all traces of it.

Installation of internal or external filtration systems

Internal filters :

are placed in the aquarium and have the role of hosting the filtering masses. The water is passed through with the help of an air stone or a pump. This water comes out clean and healthy and returns to the aquarium. The internal filters are usually fixed by suction cups in the bottom of the aquarium. Some internal filtration systems only pass the water through mechanical filtration while other systems will offer multiple compartments allowing the user to choose the filtration materials they prefer.

Internal filters are a good solution for mechanical filtration and are an excellent back-up filter. The price-performance ratio is low but it is not very aesthetic in the aquarium. The suction cups will need to be changed often to maintain good adhesion to the walls. The filtration surface of an internet system is relatively limited.

External filters :

are placed outside the aquarium and come in two forms: open external filters and closed external filters. External filters are increasingly used by aquarists. They offer a greater choice of filter media materials and have a higher flow rate.

The open external filter is a container hung on the back of the aquarium on the top. A long hose enters the aquarium and draws the water into the filter by means of a pump. The water thus passes through all layers of filter mass and returns cleaned to the aquarium. The open external filter allows mechanical, biological and chemical filtration. Its price-performance ratio is excellent and maintenance is very easy but frequent. This method is ideal for small and medium sized aquariums because its filtration surface is limited. It is necessary to plan the necessary space at the back of the aquarium and to choose the right model because several models have the disadvantage of returning partially cleaned water.

The closed external filter has a much larger container than the open external filter and is hermetically sealed. It is placed under the aquarium and 2 hoses penetrate the water. One of the hoses carries the water into the filter and the other returns it to the aquarium with the help of a pump. The water travels through the different layers of filter media before returning to the aquarium. The closed external filter offers a high flow rate and allows all types of filtration. Maintenance is less regular and relatively simple to perform. It is suitable for large aquariums as it offers a large filtration surface. In addition, the closed external filter is discreet and silent. However the cost at purchase is quite important and the method consumes a lot of oxygen.