Aquarium Water Purification (Fish Tank Filters)

Any aquarist is interested in the fact that the plants and fish living in the aquarium are healthy, do not hurt anything, there is clear water in the aquarium, without any impurities that can damage the plants and fish. But, in the sublunary world there is nothing ideal, and the very existence of fish and plants suggests that in the habitat of their habitat (in this case, an aquarium), the remnants of their own vital activity will be collected, which will poison them themselves. In huge reservoirs – seas, oceans – this problem was solved by nature, and at home the owner of an aquarium should act as mother nature. And in order to purify water from organic and inorganic impurities, it is necessary to install filters. Our article will be devoted to this.

Purpose of filters in an aquarium

The purpose of filters is to purify water from particles, mucus, chemical elements, feed debris, waste products of fish and other organisms. The filter consists of a pump that pumps water through the filter, and, in fact, a filter with various filter elements. Filters perform two functions. The first is the mechanical purification of water from suspended particles. The second is biochemical water purification. For example, filters must completely remove ammonia from water, or convert them to less dangerous nitrates. If the maximum level of ammonia in water is 0.01-0.02 mg / l, then the maximum nitrate in water, even for the most delicate fish, is 300 mg / l.

Fish Tank Filter Types

Aquarium Water Purification (Fish Tank Filters)

The filters are divided into internal, they are in the aquarium, and external, which are outside the aquarium. Still distinguish bottom filters, but this is just a kind of internal filters.
In addition, filters on cleaning methods are divided into mechanical and biological. But, at present, these two functions are trying to combine in one device in order to save the space of the aquarium.

Aquarium Filtration Systems

Adsorption system

Adsorption is the process by which substances found in water are absorbed by porous bodies. The most famous such substance is activated carbon. It is recommended to use birch activated carbon, because coals from other wood emit harmful substances. Activated carbon is not a panacea for all types of pollution, although it does its job well. It perfectly filters suspended organic and inorganic particles, peptides, retains ammonium and nitrite. Unfortunately, coal is quickly clogged with dirt, so it is usually used in the last stage of cleaning. Therefore, coal granules must be checked, cleaned, replaced.

Chemical filtration

Natural zeolites or synthetic ion exchange resins are used as filtering materials. They bind harmful substances – ammonia or heavy metals. Cleaning these filters is also necessary for an aquarist.

Peat filtration

Peat filtration is rather a way to reduce the hardness of water, by acidifying it, and thereby regulating the multiplication of certain bacteria. However, there are fish species that prefer a clean and acidic environment. For such, the use of peat as a balm for the soul. The water that passes through the peat acquires an amber shade. This must be borne in mind if you use peat.

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Flotation system

This kind of filtration removes impurities with foam. It uses the effect of adsorption of substances on the film of balloons passing through the water column. Flotation units or flotation units pass water through themselves, saturating it with air bubbles.

Aquarium Water Purification (Fish Tank Filters)

The resulting foam is collected in dust collectors and disposed of. Clean water enters the aquarium or other cleaning stages.
Two types of flotation are used – direct flow and countercurrent. Direct-flow type – water and bubbles moving in the same direction. The countercurrent type is water and the bubbles move in opposite directions. This type of flotation is currently the most widespread.

Diatomaceous filtration system

It is used to purify water from particularly small particles. Diatomaceous earth is used as a filtering element, obtained by crushing diatom shells (these are microscopic algae), hence the name. The diatom filter is equipped with a pump powerful enough to overcome the resistance of the filter.

Osmotic type of filtration

Osmotic filters are equipped with membranes that allow only water molecules to pass through. Everything else is eliminated by them. Naturally, to allow water to flow through the membrane, it is necessary to maintain a strong pressure on the reverse side. Filters are quickly contaminated, therefore, require constant attention.

Deionization principle of water filtration

The principle of operation of these filters is that a positively charged hydrogen ion H + is combined with a negative OH– ion, with the help of chemically active reagents. The result is a water molecule. This process continues as long as there are enough ions in the ion-containing resin. Then the resin is changed.

Internal water filter

The name of the filter indicates its location – this filter is located inside the aquarium. This significantly reduces the length and number of communications. As a rule, such a filter consists of a pump (hermetically sealed), and a filter element (box, cistern, etc.) through which the pump pumps water. Foam rubber is often used as a filtering element, but not simple, but waterproof. Basically it performs the tasks of mechanical water purification from impurities. The filter can also perform tasks of biological and chemical filtration. In addition, it can be used to aerate water. Which of the functions is the main, is solved in a specific situation. Since the internal filters have a small capacity (up to 1200 l / h) and a filter element volume (700 sq. Cm), they are used in aquariums up to 200 liters.
The principle of operation of the internal filter is as follows. Water from the outlet nozzle of the filter is directed along the walls of the aquarium and creates a circular flow of water, of course, not too strong, we do not need a whirlpool. Water with particles of dirt is sucked into the filter and cleaned and then re-enters the aquarium.
About filter performance. To achieve biological equilibrium required performance of 1.5-2 volumes of the aquarium per hour. Well, of course, the effectiveness of the filter depends on the volume of the filter material.

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Varieties of internal filters

Internal filter with airlift

This is one of the simplest design filters. It consists of a pipe and a piece of foam rubber, to which a hose from a microcompressor is connected. Foam rubber performs mechanical water purification. The performance of such filters is not very large, so I often use them in aquariums for growing fry.

Internal filters with pump

The principle of operation is the same. Pumped water is pumped into the filter and passed through the filter material. Such filters need to be selected with care, as a filter with excess power can turn an aquarium into a boiling sea. Adjustments of water flow from the outlet nozzle are available, but the adjustment range is small.

Internal biofilters

This type of filter purifies water, both mechanically and biological. The filter is divided into several chambers in which there are various filtering materials: foam rubber, nylon wool, activated carbon, ceramic filler.
The water that goes through this labyrinth deprives all mechanical suspensions, loses smell, color, gets rid of humus, phenols, chloramines, nitrogen compounds, and much more that spoils the life of plants and fish in the aquarium.

Internal filter pumps

The advantages of these filters are compact and high performance. For an aquarium, filters are selected that are capable of pumping at least one volume of the aquarium in an hour, or even more.

Bottom filters

Since they are located at the bottom of the aquarium, but they must be attributed to the internal filters. And it is better to install it at the very beginning, while you have not yet begun to exploit the aquarium.

The design of the filter is simple, but cumbersome. The lower platinum is a perforated structure for the passage of water. Installed at 2-3 cm from the bottom of the aquarium. Ground is poured on top – the particle diameter is 2-4 mm, the layer thickness is 5 cm. With the help of a pump, a stream of water is organized. It can be both direct and reverse. The filter is ground.

First, he performs mechanical filtration, and then, when beneficial bacteria settle, then biological.

External filters for aquarium

As you understand, these filters are located outside the aquarium. By the method of filtering, they can be very diverse (methods of filtering are discussed above). But, since these filters are located outside the aquarium, there is no need to select the space of the aquarium in fish and plants, and therefore external aquariums can be quite large, although this is not the rule. In external filters, they often combine several filtering methods, although, again, they can perform only one type of filtering. What filters you use in your tank, you decide.
We will not describe all types of external filters in detail, but we will dwell on some subtleties of some filters.

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External biofilter

The basis of this filter is the substrate on which the colony of bacteria breeds. The effectiveness of this filter depends on the area of ​​the substrate (the more the better), uniform irrigation with water to be cleaned, being in a sealed compartment to maintain a constant humidity. They have a filter at the level of the surface of the water, and it enters the filter itself, and is removed by the pump. When choosing this type of filter, you need to pay attention to the performance of the pump, the quality and volume of biomaterial, the design of the filter.

Materials used in biofilters:
– porous sponges;
– ceramic tubes;
– substrates for breeding colonies of bacteria;
– granulated coal.

Division of external filters by performance

Canister filters

They consist of a pump located in the upper removable part of the filter and a canister containing the filtering substance or material. They are located below the aquarium, and the water in them enters by gravity, and is removed by a pump.

Waterfall filters

They are mounted on the wall of the aquarium outside, the pump pumps water into the filter, and after cleaning it falls freely into the aquarium, forming a kind of waterfall.

Criteria when buying a filter

The ideal filter should be:
– silent;
– quickly and accurately clean the water;
– reliable (do not break);
– easy to install;
– easy to clean;
– and, of course, do not cost as a Mercedes, i.e. be available for purchase by an average aquarist.

Whether it will be external or internal, in fact, does not play any role, it is just a choice of the aesthetic type of aquarium. The main thing is the performance of the pump and the volume of the filtering medium corresponding to the volume of the aquarium and the number of its inhabitants. Optimum pump performance – pumping the volume of the aquarium in one hour. Of course, not bad, so there was a margin of safety, in case you decide to install a larger aquarium. But in this case, the pump performance must be regulated.
Since filters operate around the clock, filter reliability is an important parameter. If the pump fails, and you do not notice it in time, instead of good bacteria, especially biofilters, bacteria will multiply, which can cause irreparable damage to your aquarium dwellings.

Care of aquarium cleaning filters

As with any device, filters need periodic cleaning. Typically, the manufacturer indicates this frequency, but when choosing a moment to clean, you need to consider how intensively your filters worked. This period may have to be shortened. If you have a multifunctional filter, do not clean them all at once. This will open the gate to the aquarium for the “enemies”. Even foam filters are cleaned in parts so that the growth of beneficial bacteria responsible for the nitrification of water resumes in the cleaned part. Ceramics washed parts, with an interval of three months.