It is believed that the effectiveness of the external filter depends on its performance and design. Although practice shows that this is not the case. The most important conditions are the following: the correct calculation of the density and composition of the fillers, the maximum possible area of the filtering surface, and finally, the regular intensity of water passing through each section.
The velocity of the water and the volume of the filter should correspond to the volume of the aquarium, taking into account its size, the number of fish, as well as their appetite, not forgetting to take into account the requirements for the movement of water. The filter should not be too powerful, because the fish will feel like in a centrifuge, the fry can easily be pulled into the hose. If the filter will be of weak power, it will not be able to cope with blockages. It is important to keep in mind that during operation the performance of the filter will decrease. The final choice of external filter for the aquarium should be done based on the filter performance. If you need to provide filtration with a large aquarium, then it is better to put 2 small or medium filters in it, instead of 1 large – this will purify the water much better.
In the aquarium market there is a wide variety of filters to choose from, there are some that combine two functions: an aerator and a filter. But it would be more correct to purchase such mechanisms separately, so that the health of the aquarium could not depend on one element. The external filter needs to be cleaned many times less than the internal one, but the process itself is rather complicated.
No matter the external or internal filter you purchase, it is important to pay attention to the manufacturer of the filter. Often, there are no spare parts for Chinese-made filters at all, so by purchasing such a filter you need to be prepared for the fact that you can be left without it after a week, in the event of a breakdown, for example, clip-clips. This is one of the reasons why it is worth paying more for the filter on which in the future it will be possible to choose spare parts.
The internal filter is located in the pond. Such a filter is a simpler option and it is often used by novice aquarists. As the filter material is usually used cheap foam.
From time to time you need to get it, remove the accumulated dirt and rinse under water. It happens that these filters are made in several stages, using different materials for sequential cleaning. In the pre-cleaning, large particles are removed, and already at the next stage, the removal of fine dirt. Absorbent materials are sometimes used as grade 3 purification.
An external filter for the aquarium is mounted outside. The external filter is a more complex device, which includes a number of stages of biological and mechanical cleaning. It is used only by experienced aquarists when it comes to keeping naughty fish.
The external filter can function for a long time without maintenance. When cleaning it, rinse only the steps of mechanical water cleaning.
The volume where nitrifying bacteria live does not need to be touched in order to preserve their colony. When using the external filter, you need to look at the reliability of all its connections, as well as the device itself, since water can be easily drained from the aquarium to the floor. Such filters should be purchased only from reputable, trusted companies.