Many novice aquarists make quite serious mistakes. Among the questions on thematic Internet forums can be found phrases like this: "the filter almost always works ….". Here lies the important and very standard mistake of novice aquarists. The filter should always work. Turning it off is pointless and harmful. To agree with the correctness of this statement, you need to understand the filter device.
Fish Tank Filter is a device consisting of two parts: a turbine head, that is, a water pumping pump, and a cartridge with filter media. The filters are divided into internal, which are placed directly in the aquarium, and external, connected to the aquarium with hoses. In the latter type of filters, the volume of the filtering material is larger and it is located there much more intricately. The principle of operation of all filters is the same: they pass water through the filter material.
Filters are designed for mechanical purification of water from turbidity and chemical purification of water from waste products of the aquarium population, as well as for mixing water. Small filters perform mainly the last function, since there is little filtering material in them. A strong jet from the filter head creates a current in the aquarium, and if the filter is placed correctly, the upper and lower layers of water will mix, and the gas will be exchanged with the room air. Thus, in aquariums there is no stuffy stagnant zone and the fish do not stand at the surface of the water, but are evenly distributed in depth, since the concentration of gases is about the same everywhere.
The design of many filters makes it possible to put an air intake tube on the spout of the filter, from which the jet captures many small air bubbles. So the air as if forcibly gets into the water column and saturates it with oxygen. However, it is important that air gets out of the room, and not from under the closed aquarium cover. Otherwise, air will flow into the water, which has already given up all the oxygen and is saturated with carbon dioxide, which can quickly lead to the death of all the fish, especially if there are few or no living plants in the aquarium that additionally release oxygen.
It would seem that the principle of the filter is simple and clear. The filter material retains dirt, gradually clogging, because of what it is periodically necessary to clean. However, if you clean the filter by washing it with warm water, then the water in the aquarium, alas, will not become transparent, but will contain more and more nasty white mud. The thing is that the filtration process consists not only of the mechanical phase, but also of the biological one. The mechanical phase consists precisely in the fact that particles of dirt are trapped on the filter material. But the filtering process does not end there. Bacteria saprophytes, which decompose dirt to simple mineral substances, come into play. Ideally, water, carbon dioxide, nitrates and some other substances remain. This is the biological phase of filtration. Water transparency can only be achieved when this phase is fully implemented. However, in the new filter, the required number of microorganisms does not have time to settle immediately, and if it is also washed regularly, then it will not happen very soon. Because of this, the semi-decomposed dirt will fall back into the aquarium, and the microorganisms that feed on it will divorce around the aquarium, making the aquarium water whitish-muddy. It is rather difficult to correct this situation, since the filter practically does not delay these bacteria, and it is impossible to filter them out. You can wait until the correct bacteria settle in the filter, which will successfully process the dirt entering the filter. Then the bacteria in the rest of the aquarium will have nothing to eat, and they simply die.
Thus, it should be remembered that the Fish Tank Filter should be washed only when necessary, in cases where an increase in sludge will interfere with the pumping of water. In no case can not use detergents. You can rinse it in the water that you download from the aquarium during the substitution.
When installing a filter in a new aquarium, it is best to use the old filter from a prosperous aquarium. So the process of establishing a biological equilibrium will accelerate several times.
Just in the fact that bacteria live in the filter that are useful for water purification and the reason is that it is absolutely impossible to turn off the filter. After all, without a constant flow of water, these bacteria will die and anaerobic microorganisms that release hydrogen sulfide and methane will settle in their place. Running such a filter makes it very easy to poison the fish.