Purpose aquarium filters – mechanical, chemical and biological water purification. It should be noted that the design of the water filter involves a large surface of the filtering medium. Aquarium filters happen internal (located inside the aquarium) and external.
Currently for freshwater aquariums The last type of filter is the most popular.
Filters for water work with the help or air flow (principle of airlift), or electric pumps. Significantly cheaper filters of the first type.
Novice aquarists in most cases highly overestimate the amount of filtration that is required to maintain aquarium good water quality. Veterans, who are interested in aquarism even at the time when only a few people could afford to buy an electric filter, know that a large amount of waste is biologically capable of handling and a filter that works due to air flow.
The only thing that this cleaning can not perform, so it is to collect all solid waste and maintain the transparency of the water.
The main parameters of the filter are the speed (capacity) and volume of pumped water. The performance of electric filters is usually fixed, for example, 300 l / h.
When selecting a filter, it is necessary to take into account the following parameters: the volume of the aquarium; load, that is, the amount of waste being treated; preferred for the “population” of the aquarium water flow. By the way, the size and power of the filter is not yet an indicator for its universal use in all types. aquariums. Of course, an excess of the volume of the filter medium will not damage, but the flow of water created during this may cause aquarium fish a state of discomfort and stress, or fry and small fish can be pulled into the filter and they will die.
For example, a filter with a capacity of 300 liters per hour, in a 600 l aquarium, will run water through itself in two hours, the same filter in a 50 l aquarium will do it in 10 minutes. For fish, it’s like living in a washing machine. On the other hand, insufficient filter power will cause turbidity and quick water clogging and, therefore, water will need to be changed several times more often.
In addition, due to a decrease in the biological effectiveness of a filter, a colony of bacteria that lives in it may die. More versatile – a filter that allows you to adjust the rate of flow of water.
Due to this, such filters can be used in different aquariums inhabited by fish of different species. All airflow filters are regulated by changing the air supply.
Some electrically operated filters are equipped with a flow rate regulator.
Most often in the trading network you can find these types of filters:
External filter suspension or waterfall. This is a plastic, sometimes consisting of several sections, box placed outside. In the action of such a filter can be driven by air flow or a centrifugal pump.
This filter is not very popular in Europe, but very complex electrical models are often used in the USA. The water in the filter is fed from the aquarium and then, after filtration, is drained back.
In the second variant, water is pumped out of the aquarium using a pump, and then the drain drains back above the water level.
Air lift filter It is a small plastic container that has the shape of a cube, a vertical cylinder or a triangular pyramid. The filter works on the principle of airlift.
Water enters the filter through a perforated cover, passes from top to bottom through the filtering material, then after rising along the airlift, it goes outside. These filters were not so long ago very popular, but then they were superseded by new other types of filters.
Currently, air-lift filters are mainly used to work in small aquariums, as an addition to the main filtration.
Filter canister It has the shape of a vertical cylinder (or a rectangular box), on top of which is an electric pump. This is an external filter type.
Water from the aquarium enters the flexible plastic tubes and is pumped through the filter material through the pump. A flute divider is sometimes connected to the outlet – a rigid plastic tube with water-cutting openings that can be placed both in the water and above its surface. These filters are available in various capacities and sizes.
Most models are equipped with a performance regulator. For small aquariums, this filter is not suitable.
Filter cup – plastic cylinder, the walls of which are perforated and inside which are cartridges. It is located inside the aquarium. The electric pump is located above the filter cup.
Some of the commercially available filters of this type are equipped with a capacity regulator. It is not recommended to use the filter cup in spawners, as it can tighten the fry.
“Head” – attached to the filter system, in particular to the bottom filter under the ground, centrifugal pump. Some models of the “heads” allow you to change the flow rate of water, in most cases it is very powerful pumps, the use of which in small aquariums is simply not possible.
Foam separators, the basis of the action of which is the air cleaning process: protein substances trapped by air bubbles and other pollutants, getting into the upper part of the device, accumulate in a removable bowl in the form of foam. The sticking column in salt water is most effective, its freshwater “brothers” have practically no real benefit.
Sponge filter – one of the most primitive and first designs of an air-lift filter, however, at present they are very popular, especially widely used in spawning. This filter is a perforated plastic tube with sponge cartridges attached to it. Contaminated water passes through a sponge filter and exits through a tube.
Most aquarists force a sponge filter to work constantly somewhere in the general aquarium, thereby maintaining the biological function of the sponge, so that if necessary it can be used in a spawning or quarantine aquarium.
Jet filter It consists of one or several perforated trays with a filtering medium, which are located above one another above the aquarium. The water returning from the filter canister is sprayed through the flute tube onto the filter material of the upper tray, flows through all the trays and returns to the aquarium. The advantage of this filter is that the water passing through it is saturated with oxygen.
In addition, the use of at least one tray reduces turbulence in the aquarium.
False bottom or bottom filter, consisting of a plastic plate with perforation, placed on the bottom of the aquarium under a layer of soil. The plate is connected to the lifting tubes, which rise above the ground and end near the surface or on the water surface itself.
In this case, the filter layer is the soil, the thickness of which for the best effect should be at least 60 … 75 mm, and the size of the soil grains – 4 … 5 mm. This type of filter is reversible, that is, the flow can be both direct and reverse. In the first embodiment, the water, passing through the substrate, rises along the lifting tube.
In the second variant, water is supplied through a tube downwards, it passes through a layer of gravel and rises upwards. In motion, the direct flow is driven by an external filter or “head” operating in the reverse mode (this mode is not available to all models!). When operating in direct flow mode, the entire soil surface becomes an “inlet” and all solid waste is captured during the filtration process, which is undoubtedly an advantage of this mode, but this also leads to clogging of gravel with neutral residues.
When operating in reverse flow, solid contaminants enter the external filter. In this case, the substrate works as a biological filter. Although the process of biological water purification mainly occurs in the canister.
It is impossible to start a false-bottom with a very fast current of water, since this entails leaching of particles from the ground or being drawn in through the filter medium and further ascent through the lifting tubes.
As additional filter most aquarists use aquarium plants, which absorb not only organic matter, but also process such toxic substances as ammonia, nitrite, nitrate and carbon dioxide into oxygen. All removed plant matter is used for growth.
In addition, plants absorb organic matter that causes growth of algae. It is recommended to use unpretentious, fast-growing plants as a biofilter: the faster it grows, the more it processes organic matter; the simpler it is, the easier it is to grow it.
It should be noted that filtering by plants is a rather complicated type of filtration and therefore it is better for novice aquarists to use conventional filters (at least, before gaining a certain experience in growing plants).
If not prohibited by the instruction manual, the following materials can be used in all types of container filters. There are such types of filter material:
Calcium carbonate increases water hardness and buffers or increases acidity. It has the form of coral chips and sand or limestone rubble. It can also act as a biological or mechanical filter.
Before use, calcium carbonate is rinsed with water to remove dust from it; this material can also be washed and reused from time to time.
Activated carbon – specially processed charcoal – used to remove heavy metals dissolved in water and certain types of medicines (in particular organic dyes, for example, methylene blue). Contrary to popular belief, this material can not remove the nitrogen cycle products – ammonia, nitrites and nitrates -.
Such material can be used for biological and mechanical cleaning. The principle of operation of activated carbon is based on adsorption: pollutants accumulate on its surface.
Since the amount of adsorbed substances is limited, coal must be periodically replaced. Due to processing, the porosity of the coal increases, and, consequently, increases the adsorption capacity.
Coal before use must be rinsed with water.
Ceramics. Most of the ceramic products, in particular hollow tubes, can act as a biological and mechanical filtering medium, since they do not clog for a long time and allow water to flow well.
Usually they occupy the first section of multisectional filters. After washing, they can be used again.
Synthetic threads. Although at present nylon yarn is considered an obsolete tool, it is still a fairly effective and inexpensive filter material that performs mechanical and biological cleaning.
Synthetic threads can be reused.
Sponge. Inexpensive and effective material for biological and mechanical filtration of water. Available in the form of cartridges that are attached to certain types of filters.
After washing, the sponge can be reused, but it loses elasticity over time. Only a special filter sponge is suitable for use in aquariums; any other type of filter sponge can be toxic to fish.
Gravel. As a mechanical and biological filter, any type of well-washed gravel can be used, with the exception of easily clogged sand. If the gravel is not inert to water, i.e. does not increase its rigidity, it can also be used as a reactive filter.
To use such a filtering material can be infinite, just wash it.
Peat It is often used as a chemical medium that lowers the acidity index. It can also act biologically and mechanically.
It paints water in the color of tea, which seems natural to many fish originating from acidic waters. To avoid the penetration of peat into the water of the aquarium, it must be placed in a nylon bag (for example, a nylon stocking) before use.
Before using such a bag rinsed in water, washing away the dust. A cheaper alternative to special peat for aquariums is saddle peat not treated with special means and without additives.
Presence of fertilizers, insecticides, herbicides, etc. in garden peat can lead to illness and death of fish.
Sintered glass – this is an extremely porous glass that has received such properties after special treatment. Due to the porosity, the area inhabited by colonies of bacteria increases.
It turns out very effective biological filter. It is not recommended to use such material as a mechanical cleaning, as it clogs very quickly.
It follows that in order to remove mechanical suspensions glass must be preceded by filtering material, for example, a sponge layer. Sintered glass is a costly filtering material, but in terms of efficiency it is superior to a much larger amount of gravel, sponges, synthetic fibers, etc.
Zeolite – this is an ion exchange resin. Acts as a chemical filter that neutralizes ammonia.
It can also be used as a mechanical and biological filter material. The service life of the zeolite is limited, but is easily restored by soaking in concentrated brine during the day. Before re-use, rinse with fresh water.
Zeolite should not be used as a biological filter filler on a daily basis, since if it is completely “worked out” in the aquarium, an ammonia crisis will occur. This material is more suitable for use in aquariums insulators, where a medicine unfavorable to biological filters is used, or in tanks for transporting fish, so that fish do not poison themselves with their waste during long journeys.
From type filter material depends on the schedule and care for him. Materials that do not have a biological effect and are used only for mechanical purification of water must be cleaned regularly, and sometimes often enough so that the captured solid particles do not have time to decompose into toxic elements. The materials used for chemical cleaning require periodic renewal, but until this point most of these materials are subject to maintenance after cleaning, for example, crushed limestone, it is enough to rinse to restore its function.
When caring for the biofilter, only a part of the material is cleaned or replaced. If you completely clean or replace the filter medium, the aquarium will remain without bio-protection until the bacteria population regains its size.