How Does An Fish Tank Filter Work?

How to install and use Fish Tank Filters

The Fish Tank Filter performs a cleaning function, removing chemical and mechanical impurities from the water. In order for it to function correctly, it must be correctly placed in the tank. The life of all the inhabitants of the aquarium depends on his work.

How to put internal filters?

Internal filters are installed inside the aquarium. The most popular – internal pump filters and airlift. They are inexpensive, they are easy to install yourself, they are convenient to use during operation. However, these mechanisms have their drawbacks – they must be cleaned of dirt almost every day, they are overall and noisy. Before purchasing such a water purifier, determine whether it fits in your tank.

How Does An Fish Tank Filter Work?

Will it be possible to install the internal filter correctly the first time? Completely if you carefully read the instructions. The device must be placed in the tank when it is half filled with water, when there are plants planted in the soil. Before turning on the filter in the network, it should be assembled in parts, and mounted on the wall or above the aquarium.

Water purification devices such as internal filters should be completely immersed in the aquatic environment. Above the filter should be another 3 cm of water. The device itself should not touch the bottom. If you bought an internal filter, or made it yourself, then attach it correctly using suction cups to the glass wall.

See how to disassemble, assemble and install the internal filter.

Included with the branded filter is a hose for air supply. In the homemade device, it should also be present, however, the principle of attachment is the same. Take one end of the tube and attach it to the special opening of the filter, the other end of it out above the water and fix it with the help of the fastened material to the upper edge of the tank wall. The tube must be above the water level, otherwise the air will not be properly sucked.

How Does An Fish Tank Filter Work?

On the tube or directly on the filter should be an air supply regulator. Its location affects the flow of water in the aquarium. After installing the water purification device, the regulator should be correctly placed in the middle position. Then watch the behavior of the fish – some will love the flow of water, others will avoid it. Adjust the water flow level so that the fish feel comfortable.

Internal cleaners should be installed after they are completely immersed in water. Before you get it out of the water for cleaning, the device must be disconnected from the power supply. Also, do not leave the mechanism turned off in the water, and turn it on after a long period of stagnation (if you did not have time to clean it).

How Does An Fish Tank Filter Work?

How to put external filters?

External filters are more bulky, and more expensive for the price. Despite the financial costs, these types of water purifiers have many advantages. The most important thing is fillers, which consist of filtering materials. Periodically they need to be replaced, which is quite simple to do.

See how to clean and replace the filler in the external filter.

External cleaners are not very noisy, they are suitable for spacious aquariums from 100 liters and more, they provide a biological method of water purification. In such an apparatus there may be several fillers: stones, sponge, rings, etc. Therefore, experienced craftsmen with the availability of skills make external filters with their own hands. The principle of operation of the external system of cleaning the reservoir: the aquarium water gradually pass through a special tank, in which there is a filler of filter materials. Then purified water flows back through the tube to the tank.

How Does An Fish Tank Filter Work?

Clean this device is not difficult. The cleaning process should occur in the aquarium water itself, which must be drained into a separate container. Further filtering matter is gradually replaced. For example, a sponge cannot be replaced completely, but only a part of it. Cut off half of the old sponge and put a new one in its place. After a few days, useful bacteria multiply in it, and the biological environment will not be disturbed.

How Does An Fish Tank Filter Work?

To install an external device for water treatment correctly, you need to read the instructions. If it is homemade, then it must first be assembled by placing all the fillers with sponges in their cells. It is also required to close both taps where the tubes are connected.

The device will be able to function properly if it is installed below the water level (20 cm). To the external filter are 2 tubes that take water and release it. They need to be fixed on opposite corners of the tank. When all parts are connected to a fully assembled device, it will need to be filled with aquarium water using a drain. Otherwise, the air from the tubes will not allow the device to function properly.

How Does An Fish Tank Filter Work?

To release the air plugs, you must connect and open a hose that takes water. Wait for the filter to fill with water. Do not allow water to flow out of the hole for the second tube. After filling the unit, turn off the inlet hose.

After that, you need to connect a hose that releases water. To do this, turn off its valve, and water will accumulate in the hose. Only after these procedures can you connect it to the system of water intake from the tank. You can later open two taps and connect an external filter to the power supply. Only with the observance of all the rules of safety and operation, the mechanism will work as it should. Never turn on the machine if you notice mechanical damage on it. Be careful in working with aquarium equipment to ensure a comfortable life for fish and plants.

Installing an external filter in the aquarium

The question of installing an internal filter in an aquarium is puzzling all novice aquarists. It seems to be all very clear, but how to do everything right so that in no case nothing happens. Is it necessary to immerse the filter completely in water or not? Why this transparent tube? And after all, what is the most interesting instruction to filters is not always clear and detailed.

The internal filter is called because it is located directly inside the aquarium itself. The external filter is bulky and located outside the aquarium. Installing an external filter in the aquarium is not too complicated process.

The internal filter is located in the water so that there is still 3 cm of water above its level. Such a device is attached to the wall of the aquarium with the help of suction cups, which are included in the filter kit. Also, a small hose is attached to the kit, it is necessary for supplying air, therefore, its 1 end is attached to the hole on the filter nose, and the second comes out, it is possible to fix it on the upper edge of the aquarium wall using a special fastening. The main thing is that the air intake was made above the level of the aquarium water.

As a rule, on the nose of the internal filter, and some at the tip of the air hose has a regulator for air supply, which you can initially put in the middle position. During further operation, it will need to be adjusted as needed. Some of the aquarium fish love a fairly strong current, which is created by the filter, and some even can not stand it.

Read more:  Fish Tank Filter

After the filter is installed and all its details are attached, you can connect it to the network. Further, all manipulations in the aquarium will need to be carried out only while the filter is turned off, since the device is not insured against damage, and this can lead to electric shock.

When the filter is set to a low flow of water, there may be no bubbles. If you can watch a wave of water in an aquarium, then the filter works well. Water is saturated with oxygen from the surface due to the waves.

How to install an external filter? The external filter is outside the aquarium. It does not clutter up the usable water space of the reservoir, does not bring resonance into the vividness and naturalness of the underwater landscape with unnecessary adaptations and details. Therefore, developers can create the most complex and super efficient filtration system that is not limited in volume.

The best filter for aquarium: types of filtering, photo-video review

Glad you looked at this page! This means that you approach this issue correctly – first read, learn, and then make a decision. After all, this approach to the business level almost all the risks of acquiring a not-good Fish Tank Filter.

How Does An Fish Tank Filter Work?

So, before choosing a filter, you must understand, and which filter is good for your aquarium ?! For this you need to think about what fish, what plants will live in your pond, how many will be. If the aquarium is large, there will be a large number of large fish swimming in it, there will be a lot of plants, then the filter should cope with this and most effectively remove all "sewage" from the aquarium water. But, if it is a small aquarium, and you are not going to breed “sharks” in it, then I personally do not see any reason to take a filter with a powerful filter, you can do with a “standard” filter and thus save a considerable amount of money.

I think everything is clear here, so let’s move on to the next question.

Before buying an Fish Tank Filter, you need to find out what filtering mechanism is used in it.






Let’s briefly review the principles of each filter with a specific type of water filtration.

Mechanical filters and aquarium filtration

– These are the simplest and at the same time effective filters for an aquarium. Some "old-fashioned" call them "glasses." The essence of their work is very simple – the filter has a pump (motor) and an absorbent sponge. The pump pumps the aquarium water, which passes through the sponge, is cleaned. Such filtration effectively copes with the removal of large contaminants: food residues, fish excreta, residues of dead organisms, etc.

If you have a small aquarium and not very large fish swim in it, such a mechanical filter will be quite enough.

Chemical filters and aquarium filtration

– These are filters that provide filtering through various absorbents. The most common absorbent is aquarium coal. Also in the aquarium used and other absorbents – ion exchange resins, for example, zeolite. Filters that provide for the possibility of such filtering are more practical than mechanical ones. Since the pores of absorbent materials are able to absorb smaller particles of pollution of aquarium water, and ion exchange resins can effectively fight even the most harmful poisons – ammonia, nitrite and nitrate, which are formed and gradually accumulate in the aquarium.

Biofilters filters and aquarium biological filtration

– Perhaps this is the most valuable filtering for the aquarium. Its essence lies in the presence of a special compartment in the filter for breeding a colony of "beneficial" bacteria, which multiply on a special substrate, for example, ceramics. These bacteria are important and very useful hydrobionts of any aquarium. They are involved in the denitrification process, to put it simply – they feed and decompose ammonia, nitrites and nitrates to a gaseous state. And, as many people know, NO2NO3 are the worst enemies of the aquarium inhabitants, in most cases they are the root cause of the fish disease.

Combined filters and aquarium filtration

– These are filters that combine the possibility of using various types of filtration of aquarium water. Some filters have all three of the above filtering types. But it is worth noting that even the simplest mechanical filter can be used as a combined one. That is, use in it and absorbent sponge, and for example aquarium coal.

photo mechanical Fish Tank Filter

photo biofilter aquarium combined

How Does An Fish Tank Filter Work?
How Does An Fish Tank Filter Work?

So let’s summarize the above. If you have a small pond and not very big fish, then your choice is a mechanical filter. Such filters are not expensive, easy to operate and clean. But, if you have a large aquarium, large fish or just a lot of them, then our recommendation for you is to choose a combined filter with the presence of biofiltration. Such a filter is more expensive, more difficult to clean, but it will serve you well.

For those who still want to do mathematics or want to make an Fish Tank Filter on their own, here is the formula for calculating the power of the Fish Tank Filter

Buying a good Fish Tank Filter, you should also pay attention to its technical characteristics. In a word on power. The power of the filter is determined by its ability to pass a certain amount of water for a certain period of time. Usually 300l./hour is written on the filter pack, 1000l./hour – pay attention to this.

If you do not want to bother with the calculation of the necessary filter capacity, then you can simply look at the recommended aquarium volumes for this filter, which are written by the manufacturers on the packaging, for example, “designed for a volume of 150l.”. However, this figure is not always true.

Therefore, we advise you to take a filter with a “recommended volume” mark an order of magnitude higher.

A rather important technical characteristic of the filter is its “noise”. Good Fish Tank Filters are noisy, but quiet. Agree, I would not like to hear the roar of the motor from the aquarium at night, as if "a flock of night bikers travels around your bed." If possible, do not take Chinese Fish Tank Filters or filters of unclear brands. Trademarks that have proven themselves in the market, try to make their products high-quality and silent, but such filters are much more expensive than Chinese. It is very difficult to recommend you a particular firm – there are many of them, and they are not always “branded”. But, based on my own experience, I dare to draw your attention to the AquaEL TM – a combination of price and quality.

Now let’s consider the issue of choosing an Fish Tank Filter based on its location.





Internal Fish Tank Filters

Perhaps these are the most popular and best-selling filters. Their price is much cheaper than external filters, easy to operate and clean. As a drawback, some aquarists point out that they occupy space in the aquarium – thereby eating up precious volumes. However, this is a controversial point, because the filter does not occupy 1/3 of the aquarium. Well, yes, it takes 2-3 liters of volume, hanging quietly in the corner. It seems to me that this is not a very significant drawback, especially for medium and large aquariums.

Read more:  How To Handle Fish Tank Filter

External Fish Tank Filters

– these are filters that are located and installed outside the aquarium, only the tubes are lowered into the aquarium. It is difficult to give a positive or negative assessment of such a filter – someone is happy with it, some is not. Therefore, I will simply list the advantages and disadvantages:

How Does An Fish Tank Filter Work?


– a large amount of filter materials, thereby achieving maximum water purification;

– combined filtration with purification rates;


– this is a huge "bucket" near the aquarium;

– There is always the likelihood of a flood (as a rule, if the assembly is incorrect)

Mounted Fish Tank Filters

– This is a compromise between the internal and external filter. The hybrid of both is "hanging from the outside, but working inside." These filters are not so popular among aquarists, because they work according to the principle “not yours is not yours,” perhaps its only distinguishing advantage is compactness and space preservation both in and under the aquarium.

How Does An Fish Tank Filter Work?

So, summing up the above, we can recommend internal filters for small, medium and not very large aquariums (up to 200 liters). For large aquariums, external Fish Tank Filters will be good. Of course, this statement is relative, because no one has yet canceled individual aspects and wishes.

Concluding this article, I would like to note that there are other methods, mechanisms for filtering aquarium water, such as – a bottom filter or “false”. Such methods are less popular and have a number of advantages and disadvantages. In the future, if necessary, you can make them yourself.

I want to believe that this article has helped you determine the choice of the best Fish Tank Filter. But, remember that no even the coolest filter will not replace the banal weekly replacement of aquarium water.


Video about good Fish Tank Filters

Bottom filter for aquarium

The bottom filter is a whole water purification system that is used in aquariums of various sizes. Its main principle is water filtration in a natural way, that is, through the ground. However, there are many questions and disagreements about this method, because the main garbage remains on the surface of the ground, so it has to be periodically washed. So, consider everything in order.

Bottom filter design

This type of filter is an unusual system. It consists of

  • lattices with small cells (either from a thin plate with small holes),
  • pumps
  • tube systems.

The tubes are located at the bottom of the aquarium, the grid or plate is placed on top, and then a layer of soil.

It should be noted that in this case it is impossible to apply sand and shallow soil, because it will clog the holes through which water is circulated. At installation of the bottom filter small pebbles or small pebbles are poured on top.

How does the bottom filter work?

The principle of operation is very simple:

  • the pump drains the water out from under the grate,
  • then it is cleaned through a special filter element and returned to the aquarium;
  • then the water re-seeps through the ground, undergoing a rough cleaning, and the process begins anew.

In the tubes, which are located at the very bottom (under the plate), there are small holes through which water is drawn. Optionally, you can optionally install a tube with an aerator. Thus, not only the filtration, but also the aeration of the whole soil will be carried out.

Advantages and disadvantages

Before installing the bottom filter should be familiar with its features. Of course, the first minus will appear immediately. To install the system, it is necessary to completely drain the water from the aquarium, remove the soil and all the decorative elements, which takes a lot of time.

The indisputable advantage of such a filter is:

  • continuous circulation of water from the entire aquarium;
  • when passing through the soil, it stagnates at the bottom;
  • Such a water cycle allows you to avoid rapid contamination of the aquarium and the emergence of various kinds of infections.

Aeration of the soil helps the algae to strengthen and develop their root system, but when the soil is oversaturated with oxygen, leaf growth slows down. In addition, in the soil there are no nutrients for algae, they go along with the water. Therefore, this design solution is not recommended for use in an aquarium where a lot of greenery grows.

Even when using a bottom filter, dirt particles still remain on the ground surface. They do not pass through it due to its large size. Therefore, as mentioned above, you have to wash the pebbles. But you can avoid unnecessary mess with changing water and washing the soil.

For this you need to put an additional filter element that will have time to drive through all the water. Or you can buy a device – a siphon, which removes large particles of dirt from the surface of the soil (this procedure is preferably carried out weekly).

Another drawback of the system is that the holes in the tubes quickly become clogged with debris. To clean them, you need to completely pour water from the aquarium and disassemble the entire structure. For a small container (up to 50 liters) this will not cause a particular problem, but for a large aquarium it is very difficult and hard work.

How to make a bottom filter yourself?

There are several ways to build the structure itself. The most optimal of them is the method of using ordinary plumbing pipes.

Measure the length and width of the aquarium. Based on these parameters, it is calculated how many meters will be required for the manufacture of this system. It is better to take a plastic pipe of small diameter (up to 3 cm).

So, for the water intake system will need

  • 3 main pipes (their length corresponds to the length of the aquarium itself),
  • 4 connecting corners,
  • 2 tees
  • 4 small segments (they will interconnect the main tubes),
  • You will also need a plastic separator and a small funnel (a filter will be installed in it).

You can take Plexiglas as a grid, cut the required size and make holes with a drill (it is better to do this with a soldering iron, because it can burst during the drilling process).

After assembling the pipes into the desired structure, holes should be made in them. The pump, which will pump water, is installed on the main pipe. Accordingly, the closer the holes are to it, the stronger the thrust will be. So that the water is pumped out evenly from all sides, it is best to drill a little more holes on the opposite side of the pump.

So, the pipes are soldered together, the plexiglass and the main pipe with a pump are installed on top. When the whole structure is assembled, after a couple of hours it can be installed in the aquarium. After its installation, the ground is poured from above and water is poured. The system is then turned on and tested for several hours. And finally, you can please the result of the inhabitants of the aquarium.

Read more:  How To Quickly And Correctly Install A Filter For An Aquarium

Additional information on the organization of the aquarium:

How to make a fit filter with your own hands, read here.

Useful tips for novice aquarists.

Is there an alternative to the bottom filter?

Many aquarists claim that bottom filters can already be left in the past. Of course, they quite effectively clean the aquarium from contamination, but to maintain cleanliness, additional methods of care are required. There are alternative devices: external and internal filters.

Each model is designed for a specific volume of the aquarium. Also filters can include the device for aeration of air – the compressor. Such devices are able to pass through themselves the entire volume of the aquarium in just 10-15 minutes.

The advantage of such filters is quick installation and easy maintenance. To make cleaning, it is enough to disassemble it and wash all the structural elements under the faucet.


The bottom filter is an effective way to filter water, which allows it to be cleaned naturally (passing through the soil). This type of construction has both advantages and disadvantages, which is why many aquarists do not dare to acquire it. But why spend money if you can build yourself a bottom filter from inexpensive materials?

This type of filtration was known at the end of the last century, but it is still used today. Difficulties in installation and maintenance make fans switch to more modern methods of water purification using external and internal filters (the latter are attached to the inner wall of the aquarium).

Video to create a bottom filter for an aquarium:

Canister filter for aquarium

There is a wide variety of water purification devices on the aquarium accessories market, and the canister filter is one of the most common technical devices in this segment. Deciding which filter to buy, it will not be superfluous to know its design, advantages and principle of operation.

Purpose and device

A canister Fish Tank Filter is called this way because its shape really resembles a canister. Due to the fact that it works outside the aquarium, it is classified as an external filter. The device performs a full cycle of water purification, which provides for the presence of all levels of filtration:

  • biological,
  • mechanical,
  • chemical.

The principal device of the device has not changed for several decades. It consists

  • from the tank where the filter material is placed,
  • a pump that pumps water
  • inlet and outlet hose.

Nothing complicated. All other elements of the device are only the results of technical progress in the field of aquaristics, designed to provide ease of operation of the equipment and give it greater functionality.

One of the main parts of such a device is, of course, the filter element itself. It usually consists of

  • sponges (rough mechanical cleaning),
  • fine pore syntepon for fine cleaning,
  • biological substrate filler (water biofiltration).
  • In some models, a chemical filter is also installed, the role of which can be played either by activated carbon or special resins.

How does a modern canister filter work?

Outwardly, it looks like this: hoses are attached to the body of the device, they are lowered into the aquarium water. The power wire is plugged into the household outlet, the power button is pressed, the device is working. Everything is very simple. However, it is necessary to imagine what happens at this time inside the device.

At the moment of switching on, the water pump starts to work, and the liquid enters the upper part of the canister through the retractor hose, into the cassette filter, the first level of which is the sponge. Large parts of the garbage settle on it.

Then the water passes the fine filter and enters the biofilter. There is its purification from ammonia and nitrite.

Fully purified water through a one-way valve enters the cavity between the canister body and the filter cartridge, and then under pressure is fed into the exhaust hose.

There are canister devices and with the reverse flow of water – from the bottom up. In this case, the arrangement of the filter cassettes also changes, but there are no fundamental differences in the work.

Types and brands of canister filters for aquarium

German, Polish, Korean, Chinese companies produce a variety of models for aquariums, which are primarily divided by pump power and, accordingly, performance. The more powerful the pump is, the more water it can pump per unit of time.

There are devices with an external location of the pump, and in many recent models of external filters the pump is located inside the case. Such an arrangement of the working device reduces the noise to a minimum level.

Also, filters differ in overall dimensions, in case capacity, and even in shape. There are canisters not only of classical form, but also cylindrical and square. Of course, different models of devices have different costs.

Which canister cleaner to choose?

The first selection criterion is the price.

You should know that the external filters of the German brand Eheim have the highest cost. Accordingly, their quality and reliability is also at altitude.

The average price position is occupied by products of the brands Aquael (Poland), Sera, JBL, Tetra and Hagen (Germany), Ferplast (Italy). True, almost all the products of these brands are collected in China.

The budget option – models of Chinese brands Atman, Resun and some others. By the way, Atman canisters are quite decent and reliable products, the design of which was developed by American engineers, and released by the Chinese company Chuangxing Electrical Appliances Co.

The second selection criterion is the tank capacity.

And, therefore, the performance of the necessary filter, which is measured in liters per hour. An annotation for each equipment sample indicates which aquarium it is suitable for.

For example, the Polish product Aquael MiniKani 120, designed for an aquarium with a capacity of up to 120 liters, has a pumping capacity of 350 liters per hour. Of course, the power consumption of such a device is much lower than that of a filter with increased performance.

Overall dimensions of the device

As a rule, the host of ornamental fish plans in advance where the external filter will be installed. Often it is put in the cabinet under the aquarium.

An important factor is the availability of service devices and the frequency of replacement of elements. The more expensive the canister, the easier it is to maintain, clean and change the filter cassettes.

Many devices have additional options, such as

  • electronic control and adjustment of pump power,
  • built-in water heater
  • various nozzles for aeration and others. In this case, the choice depends only on the desire of the aquarist himself.

Benefits of Canister Filters

Among the obvious advantages of such devices, you can specify the following:

  • ease of use;
  • high performance and efficiency;
  • availability in service;
  • availability of a full filtration cycle;
  • durability and reliability.

The range of canister filter models for aquariums is wide. When deciding which device to purchase, it is necessary to understand that such a purchase is made for a rather long period. An efficient and reliable external aquarium water purifier is the guarantee of the health of the aquarium fauna and flora.

Especially for thrifty aquarists video, which details how to make a canister filter with your own hands: