For an aquarium to be pleasing to the eye, and its inhabitants to always be healthy, it requires careful maintenance and the use of special equipment. One of the essential attributes of a densely populated aquarium is a filter.
Aquarium without filter
Does an aquarium always need a filter? No, if there are few inhabitants in it and about 10 liters of water are used for one fish up to 5 cm in size. In this case, even without a filter, a biological balance will be established in the aquarium, and with regular removal of debris accumulating at the bottom and a weekly change of 1/10 of the water, fish and plants will feel quite well.
In an aquarium without a filter, there must be aeration, it contributes to the saturation of water with oxygen and the oxidation of harmful substances. If the population of the aquarium is large, a filter must be provided.
Aquarium filters
There are several types of filters used by aquarists. The simplest is a foam sponge, put on an air diffuser. The rising bubbles cause a slight flow of water through the sponge, and debris settles on its surface. From time to time, the sponge should be carefully removed and rinsed.
Another filter option is air-lift. The principle of its operation is as follows: the air atomizer is placed in a tube with a diameter of 1-2 cm. The lower end of the tube is located at the very bottom, the upper end is withdrawn into a small cuvette located above the water surface at the back wall of the aquarium. Many small holes are drilled in the bottom of the cuvette, from above they are covered with a fine plastic mesh, on which a layer of sand 1-2 cm thick is poured.
When the aeration is turned on, the water along with the air flow through the tube enters the cuvette. In it, it passes through the sand and flows down into the aquarium through the holes in the cuvette. This filter has several important advantages: first of all, it purifies water very well. Cleaning is carried out both mechanically, due to the passage of water through the sand, and as a result of the appearance of bacteria in the sand that decompose harmful substances. From time to time - for example, once a week, such a filter is washed. Namely, the accumulated debris is removed from above, the top layer of sand can be changed every few weeks.
Such a filter will be even more effective when combined with a bottom filter. In this case, a plexiglass sheet with many small holes drilled in it is laid on the bottom. A hole is made in one of the corners in the sheet for the airlift tube. Underlays are placed under the sheet so that there is a distance of at least 1 cm between the bottom and the sheet. The underlays must not impede the flow of water and can also be made of pieces of plexiglass.
A fine plastic mesh is laid on a sheet of plexiglass, and soil is poured on top. During the operation of the airlift, water comes from under the plastic bottom, while all the soil plays the role of a filter. Such a filter not only perfectly purifies the water, but also promotes the growth of aquarium plants.
There are also external external filters that provide a very high quality of cleaning. Water can be supplied not only by an airlift, but also by a special pump. In stores, you can buy factory filters of any type, both internal and external. The choice of a particular filter is determined by the population of the aquarium and the preference of the aquarist.
