What is an aquarium?

What is an aquarium?
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Aquariums are vessels made of glass or transparent plastic which are filled with water. There are many different types of aquariums here. The aquarist creates his own underwater world with the help of plants, animals, and soil and keeps it alive through care.

The passion for aquarists often begins in childhood with the first small aquarium. This fascinating and varied hobby is often incomprehensible to outsiders. Aquarists are constantly discovering new challenges in terms of stocking and planting, and this makes each tank unique.

Table of Contents

The structure

The structure
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Most aquariums are made of glass. Frame aquariums were the most common tanks until the late 1960s. There were also full glass aquariums but only up to approx. 20l. With the development of the silicone adhesive, the frames of that time became superfluous. Now it was possible to build aquariums in the most varied of shapes as they are known today.

The size

The size
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With 4.5 liters it is probably the smallest aquarium you can buy. This is a so-called nano aquarium. Nano aquariums are typically all tanks up to a capacity of 54l. However, nano aquariums are only suitable for fish from a size of 30l (the aquarium must be adapted to the fish!). Most of the nano tanks keep prawns or other small animals.

The top seller among the basins is probably the 60 x 30 x 30 cm which holds about 54l. If fish are kept in this tank, attention must also be paid to which fish species is suitable.  

Where is the best location for my aquarium?

Where is the best location for my aquarium?
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The best location for an aquarium also depends on the size of the tank.

A filled aquarium can weigh several hundred kilograms and cannot be moved so easily. For this reason, a few things should be considered when choosing the right location for the aquarium.

A stable foundation

The aquarium may only statically correct base cabinets are made that the load of the filled basin stand. The floor must have sufficient load-bearing capacity.

Choose a quiet place

The best location for the aquarium is a quiet place. Places where people constantly walk by or an aquarium next to the stereo are unsuitable.

Avoid direct sunlight

The aquarium should not be exposed to direct sunlight, otherwise green algae will form. In addition, the pool heats up. A place directly in front of the window is unsuitable.

Sufficient power sockets

In the best location, care should be taken to have multiple sockets next to the aquarium, as all devices require electricity.

Coordinate with the home furnishings

When handling an aquarium, a little water can repeatedly splash out of the tank. The aquarium should therefore be placed on a surface that can be easily wiped off, such as tiles. In addition, the location should be chosen in such a way that you enjoy looking at your aquarium and that it comes into its own.

What do I need for an aquarium?

What do I need for an aquarium?
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The aquarium hobby cannot ignore the technology either and the aquarist should have a certain basic interest in it. The specialist trade for aquaristics offers a wide range of technical aids here.   The filter technology naturally plays a major role here.   Classic filters are:

  • Internal filter
  • External filter
  • Mat filter

Although these filters are structured differently, they also have something in common. On the one hand, they filter the water and, on the other hand, they offer bacteria good settlement areas.

The plants in the aquarium

The plants in the aquarium
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Plants in the aquarium not only have an optical effect, but they also ensure good water quality. A wide selection of plants does not make it easy for the right plants for their own pools to find. nature should for a good mix of foreground plants, floating plants, various species of moss, and background plants are taken care of.

Foreground plants

Foreground plants act as a visual highlight in the aquarium and stay rather small. The aim here is not to block the view into the “depth”.

Floating plants

Floating plants are ideal for obtaining a natural look. However, caution is advised here, because you should avoid using too many floating plants in an aquarium in order not to take away the light from the other plants.  

Different types of moss

The moss is also enjoying increasing popularity, this is mainly due to the keeping of shrimp.

Background plants

Background plants are characterized by lush growth and are often used to effectively highlight the back wall of the pool.


Even if algae do not like to be seen in the aquarium, they are plants. If the algae accumulate, this is an alarm signal that should be taken seriously.

What do I need an aquarium mat for?

Every aquarium should stand on an aquarium mat. On the one hand, such a base offers a high level of stability. If the aquarium were to be moved and an area would no longer lie on the support surface, the strain on the glass under the weight of the water would be too great. It formed cracks that lead to the destruction of the aquarium. Furthermore, an aquarium underlay ensures that the contact surface is flat and that no dangerous tension arises. Bumps lead to inconsistent loads. For example, if the aquarium is on a hard surface, even the smallest grains of sand can destroy the bottom of the aquarium to lead. All the weight rests on this one point. However, the glass of the aquarium is not designed for a point load and therefore shatters. A base for an aquarium is elastic and compensates for these structural problems.

What material should the pad be made of or how big should it be?

There are different materials that can be used as a base. Above all, products made from elastic polymers have proven themselves in use. A styrofoam plate can also be used as a simple solution. The base should be large enough to cover the entire bottom of the aquarium. If it is a larger aquarium, several individual underlay elements should be used. This prevents material accumulations that lead to incorrect loading of the aquarium floor. Small gaps should be left between the individual elements.

What stones in the aquarium?

What do I need an aquarium mat for?
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You should think carefully beforehand about which stones you should get for your aquarium because not all species are suitable. Even if they are primarily intended to serve their purpose as decorative stones, they give off substances that are useful for the fish and plants in the aquarium.

Basalt stones, lava stones, and slate stones are particularly suitable. Limestones, pebbles, and sandstones are also suitable for an aquarium and can be used.

However, you should always make sure that the stones do not contain too much lime or oil, as this, in turn, can be harmful to the fish. Metal inclusions and sharp edges should also be avoided as there is a risk of injury.

Where can I get aquarium stones?

Stones for the aquarium can be bought at pet stores. But you can also find it in hardware stores. Of course, the stones can also be collected. However, you need a certain amount of specialist knowledge in order to choose the right stones.

Preparation of the stones

Before stones are placed in the aquarium, they should be prepared. Often it is enough to soak them in clean water for several days. Here it is also often shown if particularly lime or oily stones are in the selection, in which parts of them are detached or a greasy substance floats on the surface.

Sometimes the stones should also be boiled, especially if there are strong impurities on the stones.

Where can I put my pool on it?

Where can I put my pool on it?
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In addition to the right space for the aquarium, the right aquarium cabinet is also very important. This should be stable and be able to carry the pelvis safely. Depending on the size and weight (in addition to the pure capacity, decoration, sand, stones, etc. should also be considered) of the pool, there are various alternatives:

Small basins (up to 112 liters)

Here you can use a standard shelf or a chest of drawers. However, you should find out about the material well in advance, because many supposed wooden furniture consists only of pressed cardboard or wood chips and is therefore not too stable.

Medium and large tanks (from 112 liters)

On the larger aquariums, the main focus when choosing should base unit lies on stability. It is very important that the piece of furniture on which the pool is to stand not only has side struts but also a central strut so that the weight can be optimally carried. Such a substructure can easily be made from solid wood by a carpenter’s workshop. A cheaper option would be to simply make an existing piece of furniture “ aquarium-compatible ” by supporting it with a central strut in addition to the side struts (a piece of wood from the hardware store is sufficient here). This way the weight of the aquarium tank is optimally distributed.

What does an aquarium cost?

What does an aquarium cost?
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Aquariums are mainly used for keeping fish and reptiles in apartments and houses. An aquarium that is as beautiful as possible is essential for every fish or reptile owner, as it is the habitat for their own animals.

The purchase of an aquarium can result in high costs for pet owners.

The prices

The prices for aquariums, like any other everyday product, depend mainly on the equipment, the type and the quality. The rather smaller aquariums, which do not have any equipment, start at € 15 in terms of price both on the Internet and in specialist shops. The larger the aquarium, ie the more water the aquarium has, the more expensive the glass boxes are. With equipment and ventilation for the fish, you can spend an average of € 200 on the Internet. In specialist shops, prices can still fluctuate.

Price-performance ratio

By doing specific research before purchasing an aquarium, you can find very inexpensive aquariums that are nevertheless of very good quality. There are also offers in the individual specialist shops that are particularly impressive due to their price and the often good quality.

The costs

In summary, it can be said that the costs for a solid and average aquarium are 150 €. Depending on the size and equipment, there are also aquariums that are significantly below or above the average price.

Nitrate: what is it?

Nitrate: what is it?
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To assess the water quality in an aquarium, the nitrate content is an important indicator. As a rule, a high nitrate content contains an enormous redox voltage in the water. The consequence is growth problems in the aquatic plants and the development of green algae. With a high content of nitrate, the risk of an uncontrolled reduction to nitrite is high. Nitrite has a negative effect on the immune system and the fish become more susceptible to diseases.

Measurement of the nitrate content

There are various tests available in specialist shops to measure the nitrate content in the aquarium.

These work with three reagents and sticks that are immersed in the water. The nitrate content in mg / l can be read off by means of color comparison. In aquariums that have a high and not too coarse substrate, are densely planted, and contain few fish, low nitrate values ​​of zero to twenty mg / l are common. With these values, no nitrate has to be removed. Values ​​up to fifty mg / l are also not a problem and nitrate values up to a hundred mg / l are still acceptable, although plant growth problems can already arise. Values ​​above a hundred mg / l cannot be expected of fish and plants and the nitrate must be removed.

Removal of the nitrate

There are two ways to remove the nitrate. The nitrate can be removed with special resins, i.e. by ion exchange, or by means of bacterial denitrification so that the values ​​normalize again.

Why does my aquarium smell?

Why does my aquarium smell?
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It often happens that aquariums smell musty or even putrid. This can have different causes:

One factor can be the multiplication of algae in the basin, which has taken place over time and thus destroys or at least endangers the biological balance of the inhabitants. This increase is caused, for example, by too much food or the infrequent water change. It can just as well be that the aquarium is cleaned too often too thoroughly, which is why protective and helpful bacteria are removed. As a result, the waste and pollutants in the water increase significantly and pose a threat to the underwater inhabitants.

If these things occur, a water test must be carried out urgently, as nitrite contamination could be the case. If this is confirmed, a water change, which includes a large part of the water already contained in the aquarium, is inevitable. Constant controls and a reduction in feeding are also necessary in order not to destroy the animals’ habitat any further and to stabilize the oxygen content in the tank again. However, if the fish swim to the surface of the water to gasp for air, you should use oxygen tablets or so-called bubble stones.

Regular partial water changes are very important as a preventive measure to prevent this scenario and save yourself work. In addition, plants have a cleaning effect, which is why you should make sure that the aquarium houses a certain number of them.

Why can’t you knock on the Aquarium?

Why can't you knock on the Aquarium?
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The well-being of the fish should come first for every aquarium owner. It is a proven fact that knocking on the window can cause significant harm or even death to animals.

How does sound affect fish?

In 1996, scientists hid a microphone underwater for research purposes in order to control the sound pollution of fish. This was linked to a sound device through an amplifier. If you knocked on the window, the tape recorder turned on. How many visitors to the aquarium, in which there were rays, knocked on the window was measured in this way.

Long-term damage to the aquarium inhabitants

The experiment showed that fish are endangered because the sound pressure is much higher underwater than in the air. If you were to hit people at this volume, it would very quickly lead to hearing damage. Experts now assume that some of the deaths of ornamental fish come from knocking on aquarium glass.

Protective screens for aquariums

If you cannot rule out that children or visitors knock on the aquarium, you should attach protective panes that can be swiveled.

The very best for the well-being of the living beings living in the aquarium, however, is to keep your fingers and fists away from the aquarium glass. In an emergency, a sign helps: “Knocking can kill fish.”

Where does the aquarium come from?

Where can I put my pool on it?
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The history of the aquarium goes back to the time of the ancient Egyptians and also the Sumerians. They tried to keep fish in small ponds early on in order to bridge the time until they were eaten. However, even at this time fish were kept as an ornament. Rectangular water basins for keeping fish were created in early dynastic temple gardens. Even in small private gardens, the Egyptians created large basins in order to be able to keep fish. At that time the fish was considered an animal with divine abilities.

Around the same time, fish began to be kept as pets in ancient China. Here, as early as 770, the dissemination of documents dealing with keeping fish began. There is evidence that the domestication of the goldfish began at the time of the Song Dynasty. As early as the early years of the 16th century, the Chinese began to keep goldfish in transparent vases and thus laid the foundation for today’s aquarium.

The aquarium finds its way into Europe

In Europe, the keeping of fish was not cultivated until the 17th century. When English sailors reported on their voyages from China about the fish farms there, they began to keep fish in glass tanks here too. Initially, British scientists kept various fish in order to research them for their science. At the world exhibition in London in 1851, an aquarium was presented to the public for the first time. This aquarium was then held together using a cast-iron frame.

One year after the World’s Fair, British researcher Phillip Henry Gosse first mentioned the term “aquarium”, which he used in his celebrated work: “A Naturalist’s Rambles on the Devonshire’s Coast”. Its successor “The Aquarium: an Unveiling of the Wonders of the Deep Sea” ensured that the aquarium gained popularity.

The aquarium became popular in Germany after the publication “The Ocean on the Table” by the pedagogue Emil Adolf Roßmäßler. In this and in the following articles, Roßäßler described the keeping of fish in domestic aquariums. However, at that time there was a lack of extensive knowledge so that the fish could not be given a very long lifespan

Modern aquaristics

The keeping of fish in aquariums has changed significantly in recent years. Thanks to the ever-improving technical conditions, it is now possible to experience the living environment of fish so faithfully. The market for water filters, heaters, and other products, as well as the current level of knowledge about fish, make aquaristics a fascinating hobby. Since the 1960s, aquaristics has become a far-reaching hobby that is gaining more and more followers.

Where is the best place for the immersion heater?

In general, when heating an aquarium, a distinction must be made between heating rods and floor heating. The heating rod is attached to one of the walls of the aquarium, the floor heating is laid as a heating cable on the floor of the tank.

Choice of location for the heating element

There are several conceivable places for the heating element in an aquarium. It can be placed in a corner or on the side of the aquarium.

The choice of location depends on the position and type of filter used, as well as the size of the aquarium.

If an internal filter is used, the heating rod is placed inside the filter in order to achieve an even temperature distribution within the aquarium.

If an external filter is used and the aquarium is larger than 150cm, the heating rod should be located near the filter outlet in order to make the best possible use of the existing flow for heat distribution. The choice of location is irrelevant for an aquarium size of less than 150cm.

Furthermore, when installing the heating element, the manufacturer’s product information should always be observed.

Floor heating or immersion heater

The choice between underfloor heating or a heating element is a matter of personal preference. Underfloor heating offers perfect heat distribution, but the heat has a detrimental effect on plant growth.

Compared to floor heating, the immersion heater offers a flow-dependent and thus possibly more uneven heat distribution, but does not have any influence on plant growth.

Where is the best place for the aquarium filter?

The aquarium is the eye-catcher for every room. A well-functioning filter is an absolute must for crystal clear water and healthy fish. When setting up the aquarium, the question arises, “Where is the best place for the aquarium filter?” The location of the filter depends on whether it is an internal filter or an external filter.

Choosing the right filter

Internal filters clean the water directly in the aquarium. External filters suck in the water and treat it outside of the basin. The external filter is located in the aquarium cabinet or directly behind the aquarium and is therefore not visible. The type of filter used depends on the size of the tank. It is ideal if the water runs through the filter twice an hour.

Find the right place in the aquarium

The internal filter can be attached to the rear wall of the pool. The cable disappears behind the aquarium. It is important that the purified water emerges at the surface and thus moves the water surface. In this way, fresh oxygen, which is important for the fish, is supplied to the tank. The external filter works like the internal filter. The big difference is that the water is cleaned outside of the basin. The filter sucks in the water through a smart device and lets it flow back into the basin through another hose. The purified water supplies the pool with fresh oxygen.

What is a filterless aquarium?

A filterless aquarium is characterized by the fact that no artificial filters are attached either outside or inside. However, this does not mean that the water remains unfiltered. The task of cleaning the water is now up to the living beings in the aquarium.

There are several ways to operate a filterless aquarium. You can do without filters right from the start or, the more daring but definitely possible variant, remove the filters in an existing aquarium.

With enough preparation and observation, you can dispense with pumps and water changes in a filterless aquarium as soon as an equilibrium has been established.

How does the filtering of the water work?

The sludge (a collection of waste products) is deposited in the aquarium. The bacteria present in it convert the waste materials into minerals that can be recycled by the fish and plants.

Why a filterless aquarium?

First and foremost, it should create a more natural life for the fish and other creatures that live in the aquarium.

The way of life of the animals can be negatively influenced by additional means that serve to regulate the pH or the addition of nutrients if they are used in the wrong composition or in the wrong proportions. This can be avoided by the lack of a filter, as this creates a small ecosystem of its own, which usually requires no or fewer additives.

Aquarium filter: when is the first time to clean?

An aquarium filter circulates the water and filters it so that dirt can be collected and broken down. The first cleaning of the filter in a new aquarium should be done when the filter is so dirty that not enough water can be circulated and cleaned in the aquarium. This can be seen, among other things, from the cloudy water. Intact filters can create a certain flow in the aquarium, which some aquarium inhabitants appreciate.

The first filter cleaning

However, the aquarium filter should only be cleaned if the case described above occurs and the filter does not sufficiently circulate the water in the aquarium or if a sufficient flow can no longer be achieved.

The filter must never be cleaned too often.

Don’t clean too often

If the aquarium filter is cleaned too frequently, there will always be dirt, but every time the filter is cleaned, the bacteria that are so important for the aquarium are also removed. An aquarium will never run smoothly without these bacteria. Cleaning too often is therefore not recommended in the case of the aquarium. There is no rule of thumb with fixed time intervals for filter cleaning, as each tank is individual and the levels of soiling can vary. Over time, you get a routine for your own aquarium and the necessary filter cleaning.

Which substrate for the aquarium?

When should I change the water for the first time?

To this day, many older aquarists are of the opinion that aquarium water cannot be old enough. Nobody really knows how to answer the question of why and why. This theory certainly lacks any basis, since pollutants and toxins, primarily the breakdown substances from excrement and feed residues, accumulate in old water. However, there are some fish species that live in water that is not that clean and clear in their home and therefore tolerate older water.

The frequency of water changes

Basically, you should offer your pets the best water conditions.

The frequency of the water change depends on the number of plants and fish. If there are many plants in the tank, the change is less frequent. If, on the other hand, there are much fish in one tank, the change takes place more frequently. For the aquarium environment, it is important that the entire amount of water is not changed, but that only a quarter to a third of the original amount is replaced.

The 1st water change

If the aquarium has not been cleaned for a long time or if it is heavily soiled for other reasons, two-thirds to three-quarters of the original amount should be replaced. Incidentally, aquarium water should not be taken from ponds or bodies of water in which other fish also live. Nobody can know which pollutants and parasites pose a threat to the aquarium crew.