Filtration is the process whereby pollutants and other toxins present in a body of water are removed. 

Sources of pollutants and toxins in aquarium water include fish excrement, decaying plant matter, residues of medication and chemical additives, and dyes and metals from items that are placed within the aquarium.

Why are filters necessary?

Learn about the different types of filtration devices and how they work, so that you can select a system that will suit your particular aquarium setup best.

Fitting your aquarium with a proper filtration system (which may comprise two or all three different types of filters*) will enable pollutants and toxins to be eliminated more effectively, and thus create a healthier and more stable living environment for the inhabitants of the aquarium. 

Types of filtration systems

Filters* are basically containers that are filled with a filtration material called the media, which are available in three main forms: mechanical, biological and chemical.

Mechanical filtration is the physical process of trapping larger particulate matter floating about in the water. Common forms of media used in mechanical filtration systems include sponges, filter floss, foam inserts and diatomaceous earth.

It is important to rinse out mechanical filter media and replace it whenever necessary. This helps to prevent the biological filter media from becoming clogged with particulate matter, thus reducing the surface area available for the cultivation of beneficial bacteria.

Biological filtration media increases the surface area upon which beneficial bacteria (nitrosommonas and nitrobacter) can propagate. These bacteria are essential to an aquarium’s ecosystem as they help break down harmful waste by-products like ammonia and nitrite.

Chemical filtration employs chemical media to absorb gases, metals and other contaminants that cannot be removed with the aid of biological filtration or mechanical filtration.

The most common chemical media used is carbon, which enables the removal of odours and chemical substances from the water. Another common chemical media is phosphate remover, which can absorb phosphate, an element that encourages excessive algae growth.

Other benefits of using filters

The actions of filters not only keep aquarium water clean and safe for fish, but the functioning of the pumps used in their operation also improves water flow. 

Water movement in your aquarium is important for several reasons:

As the water is circulated throughout the aquarium, it is pushed to the surface where gaseous exchange takes place. This allows carbon dioxide to be exchanged for oxygen. Oxygen is essential to the good health of the fish, and also encourages beneficial bacteria living within the filter to thrive.

At the same time, particulate matter in the water is agitated and conveyed through the filter for elimination.

Pull-quote
“Learn about the different types of filtration devices and how they work, so that you can select a system that will suit your particular aquarium setup best.”