Modern aquariums use many different cleansing systems that can conditionally be divided into two main types, these are external and internal filters.External filters have higher efficiency and quality of water purification. They are located near the upper edge of the wall of the aquarium or under it themselves and in their device is much more complicated than internal, since they include several stages of water purification, both mechanical and biological. External filter, for example, JBL Cristalprofi Greenline E1901 can perform its functions for a sufficiently long time without service, and for their prevention it is enough to rinse the blocks responsible for mechanical water purification.
The main points when choosing an external filter are:
— the correct calculation of the density of fillers and their composition;
— filter surface area;
— The intensity of water circulation in each filter compartment.
Water circulation in the filter and its volume should be adequate to the total volume of the aquarium, taking into account the number of fish living in it, the feed frequency. Also, it is necessary to take into account the requirements for the movement of water flows. If the filter is more powerful than necessary, fish will feel in the aquarium as in a centrifuge, and the smallest can suck in a filter hose. A weak filter may not cope with blockages and will not be able to pass through the entire water volume through itself.
It is important to remember that over time of operation, the filter performance will decrease and it may be necessary to replace. Therefore, for large containers, it is better to use several small devices, replacing them as necessary than one large and powerful. This approach allows you to achieve more efficient water purification, which is already difficult with a large volume of the aquarium and the multiplicity of its inhabitants.