In small aquariums with a small number of inhabitants usually install compact internal filters.
However if the volume of a house reservoir exceeds 100 liters, for water purification it is better to use more productive external equipment.
Device and principle of work.
the External filter represents a canister with the filtering material and a pomp which continuously pumps water. Two hoses depart from a canister. Both of them go down in an aquarium: on one the polluted water comes to the filter, and on another – cleaned is pumped out.
At placement of a canister above water level a pomp is established directly in the tank with small fishes. Then it pumps water in the filter from where the last comes back to an aquarium spontaneously. The aquarian water coming to the filter is exposed to multistage cleaning. The big porolonovy or sinteponovy sponge absorbs mud deposits and by that carries out mechanical water purification. Activated carbon absorbs the dissolved waste of activity of small fishes, and the layer of porous expanded clay serves as the environment for reproduction of useful bacteria which are responsible for biofiltration.
Merits and demerits.
Before purchase of the external filter for an aquarium is important to weigh soberly its strong and weaknesses.
Treat advantages of the clearing device of this type:
there are Less efforts with service
Long service life.
the Shortcoming, in fact, only one – higher price.
Besides, it is necessary to consider that at the mistakes made at assembly, the filter can begin to flow. Therefore if you are not sure that you will be able to establish it correctly, is better to call the master.
How to choose the device?
When comparing different models of the equipment pay attention to the following parameters:
Productivity. For an aquarium less than 100 liters buy the filter with a productivity about 300-500 l/h, at the bigger volume – about 700 l/h
Canister volume. Than this figure is higher, more the filtering material is located with that in a canister and the water is purer. Quantity of compartments. The their is more, the it is more than opportunities for experiments with different types of fillers. A necessary minimum – three-four compartments.
Thickness of hoses. it is more preferable than a tube with the large diameter as sooner or later any hose becomes covered by a vodoroslevy raid from within that complicates water current.
We hope that this material will help you with equipment selection. Article is written with assistance of the website of http://www.zoonemo.ru