La aquarium hobby it has become one of the most popular hobbies. This is because fish are very gentle animals, they tend to live well at home, and they can be more interactive than they appear. If you have a calm personality and want fish at home, it is very likely that you are wondering how many fish can live in an aquarium. This is a question that depends on many factors.

However, here we will talk about everything you should take into account before calculating how many inhabitants your home aquarium will have.

TYPES OF AQUARIUMS: NEEDS, CHARACTERISTICS and FISH

Identifying the type of aquarium you want is the first step to consider when starting a home aquarium. Keep in mind that the ecosystems in which fish live are very different. Each type of aquarium is designed to house a specific type of life. It is necessary to keep fish with similar characteristics so that they can live together in a home aquarium.

At this point, when we talk about types of aquariums, we are not referring to the urn, we will talk about this later. When we talk about a home aquarium, we are referring to the ecosystem that it is trying to replicate. Reproducing this natural life at home is very important.

There are two large groups of aquatic ecosystems that we have on the planet; those of fresh water and those of salt water. Both the salinity level and the water temperature are fundamental parameters to keep fish alive and healthy. Since the type of aquarium plays a fundamental role, it is necessary to put all efforts into finding the balance of the aquarium according to the type of fish.

COLD WATER AQUARIUMS

One of the main determining factors in choosing the type of aquarium that we will have at home is whether it is a cold water or tropical water aquarium. Although the care of these types of aquariums does not represent too big problems, there are some very important differences.

Cold water aquariums are those that conserve species of fish that in their wild life conditions live in gas currents with a temperature of about 20 ºC. However, the temperature range varies between each species. Many can survive in lower temperatures for a time. However, they are more sensitive to high temperatures.

The most common fish that we see in cold-water home aquariums are Koi, Zebrafish, and Goldfish. One of the main advantages of a freshwater aquarium is that they do not need such a high investment in equipment. Thermostats are out of purchase necessary. Low temperatures are generally easier to control than high temperatures.

Regarding the fish that live in cold water ecosystems, they have certain physical differences with those of fresh water. As usual, freshwater fish have more varied and exotic colors and shapes than coldwater fish. If you opt for this option, there will be fewer options in terms of its appearance.

One advantage that fish in these types of waters have is that they are larger. This gives a more imposing and showy appearance inside your aquarium. The life expectancy of these fish is also higher and they have better resistance to disease.

FRESH WATER AQUARIUMS

For this type of aquarium you have to have two very important factors in sight; space availability and budget. Aquariums for these fish need to be larger than planned because they grow to a good size. The space in which the fish live is essential to determine their well-being and health.

Placement is very important for this type of fish. Light and temperature fluctuations are the worst option for these cases. Light sources or external temperatures should be away from the aquarium. LPlacement near windows or heating is not a good place for any aquarium. It should also be noted that accessories take up place in the aquarium. Filters, tubes and cables also take up space from the total capacity of the aquarium. The stand must also be strong enough to support the weight of a full aquarium.

Noisy areas should be avoided because fish can suffer from stress and hyperactivity in these circumstances. Continuing with the care of this type of aquarium, soap should never be used to wash the urn or the elements. Soaps typically leave residue with materials that build up and become dangerous in an aquarium. Fish gills can be burned if there is soap residue in the water.

Like any living being that leaves its natural habitat, it is important to equip the aquarium with certain accessories so that the fish feel comfortable and safe.

A filter is an indispensable piece of equipment for any aquarium. The life of the fish depends on this, because when the water becomes too dirty, the toxic agents become extremely dangerous for the fish. On the other hand, water conditioners are also a great option. They keep bacteria that can affect fish skin under control and control chlorine levels.

The elements inside the aquarium are very important because fish need places to rest and relax. These sites also help fish interact and play for a more active life.

Water cycling bacteria are very important. The water that comes out of the filter is not the water that fish have in their wildlife. It is a water that has not created the bacterial colonies necessary to maintain the chemical balance of the aquarium.

In the tropics there are more than 8.000 species that benefit because they are stable climates for most of the year. In these areas there are usually many hours of sunshine. The regions with the most abundance of this type of species are South America, Central America, Southeast Asia and Africa.

The average temperature that these aquariums must have is 24 ºC to 28 ºCAlthough because there are so many species, attention must be paid to the specific needs of aquarium inhabitants. The pH is also slightly acidic, so the water does not usually drop below 6 points, with a kH hardness of 3 or 4. Freshwater fish tend to resist nitrates found in water much better. The maximum acceptable is 10 to 15 mg / l.

Air conditioners are not a good place to keep your aquarium close by because they alter the temperature too much. Windows and sun exposure can also be too high and the temperature rises, so fish should not be exposed to these conditions.

The oxygen in these aquariums is very important. Natural oxygen levels are generally low. To increase oxygen levels there are two ways to do it; on the one hand are the plants and, on the other, the oxygen that arrives from the surface of the atmosphere of an aquarium through gas exchange.

Filters also help a lot to oxygenate the aquarium. Contrary to what many believe, it is not that the bubbles increase oxygen, but rather that the movements of the lower surfaces of the aquarium water stimulate gas exchange, and this is what does increase the overall oxygen in the aquarium. It is important to note that temperature directly affects this parameter. The higher the heat, the less oxygen available to the fish.

Home aquariums work well when they reproduce the natural conditions of the water where fish live. The lighting of the tropics is very specific and continuous. When there is too much light, it is a problem because the fish become stressed and it favors the overpopulation of algae. Low light can affect fish, but especially plants.

Timers are very important because the function of your home aquarium light is to recreate light cycles. Generally, in these regions there are between 12 and 14 hours of light during most of the year. This is the average range of daylight hours the fish will have. Although it may seem like not, the fish sleep, but if they are in focus under the light at night, they will not be able to do so.

If you have an aquarium with fish and plants, the substrate is another very important part so that they have essential nutrients. The amount, thickness and type of substrate depend on the species that are in the aquarium. Burrowing fish can greatly benefit from a substrate. some fish bury their eggs there and are often a good place for fry during their first days.

It is recommended that the substrate be placed in a higher layer at the back of the aquarium and a thinner layer at the front. In this way, a substrate-dependent species will be created.

paludarium

This is an option that is not one of the most popular, but it is a very attractive space. We are talking about a combination between a terrarium and an aquarium, but the most important thing in these ecosystems is to maintain a good ratio between the amount of water and the amount of dry land.

The canopy is a fundamental part because it is the highest part of an aquarium and it consists mainly of branches and plants. It is a very important area because the animals flee to these areas looking for more ventilation, light and avoiding the humidity of the water.

The area of ​​the earth is the one that will separate the substrate from the water. Hard pieces are often used that completely separate these two areas. The area of ​​the land must be totally dry, because the animals will seek to dry out completely. Turtles, frogs or crabs need these ecosystems to live.

The water zone provides the moisture and the aquatic ecosystem that these animals need. It is the part that is lower in the entire surface of the aquaterrarium and provides all the moisture and water that the inhabitants need.

The two most common ways to start a paludarium are to start by water or by land. Some keepers prefer to start with an aquarium and add terrestrial pieces to it. You can also start with a terrarium and separate the area from the water to turn it into a paludario.

If you do not have much experience with the care of this type of animals, it is best to start with your aquarium that is already at home. It's best to empty it completely, let it dry, and begin adding surfaces that function as land and water zones.

When the walls are completely dry, the rest areas can be added. There are glues specially designed for aquariums and firm surfaces are glued to the walls with these products. Bases can also be used to function as support for ground platforms.

Some options, among the most attractive are the land platforms, but it has serious problems. They are generally not strong enough to support the weight of most quaternary animals. They are only fine for small amphibians like the fire-bellied newt.

After having installed these zones, the water can be added as is normally done to start with the filter function, the water cycling, the regulation of the temperature, the pH, etc. One of the biggest drawbacks that aquaterrarium keepers often suffer is that cleaning the urn can be complicated. Because the surfaces make cleaning a bit difficult. Products such as water conditioners and aquatic plants can be used to extend the life of the aquaterrarium water.

There is also the possibility of converting a terrarium into an aquarium. However, you must make sure that the urn does not have leaks through which the water can escape. It should also be considered that aquaterrariums do not have as much capacity to store water, so the aquatic species must be few.

The transformation from terrariums to paludarium is basically the same as what should be done from an aquarium to a paludarium. The only fundamental difference is the amount of water they can hold. It must also be taken into account that the filters need a certain amount of water in order to function. In the event that your filter cannot be installed, more regular water changes will be necessary.

You may not be quite sure what kinds of animals can live well in an aquaterrarium. As a general rule, most freshwater fish do well in a paddock. What must be maintained is the same quality of water so that they do not feel a fundamental difference. You can also include invertebrates such as snails or prawns because they are usually one of the most common ecosystems of these animals.

The general sense of having a paludarium is to be able to introduce animals that can live well in semi-aquatic environments. A good option is crabs, but you must take into account some considerations. The dirt part has to have a good amount of sand so that they can move around as usual. The so-called "mud jumping fish" live very well in the paludaries.

Animals such as frogs, salamanders, or newts can also be included because they give a tropical and dynamic look to the whole space. However, keep in mind that many species of frogs need a good canopy to have good light exposure.

Turtles are one of the reptiles that look best in this environment. It's a good idea to bring one home only if you have enough space. These tend to grow much larger than amphibians do and can suffer a lot from not having enough mobility to develop their lives.

HOW MANY FISH CAN LIVE IN A COMMUNITY AQUARIUM?

The number of inhabitants an aquarium can have can be a bit tricky to calculate. Most urns do not come with instructions where the user can be guided on the number of fish that can live in this space. This has a reason, it is a decision that involves many considerations.

Overcrowding an aquarium is one of the main causes of death for domestic fish. It must be taken into account that fish live with their own waste, so toxic waste must be kept under control.

1 LITER PER CENTRIMETER RULE

Calculating the amount of water your fish need is a very difficult task. There are thousands of species of fish that live in home aquariums. Each has very definite characteristics, making it difficult to generalize about fish. However, one of the most basic rules that usually serves as a guide is 1 liter of water for every centimeter of the fish. This is a good guide, but it is recommended to put at least 2 liters per centimeter.

There are factors like reproduction that you should also take into account. If there are males and females in the aquarium that can have young, the number of inhabitants and their waste will increase. There are also species that "dirty" the aquarium more than others. On the other hand, some fish enjoy vertical swimming more than horizontal swimming. All of these are considerations that must be borne in mind in this task.

Another factor to take into account is the behavior of the fish. These are animals very sensitive to stress, so a calm and calm environment should be maintained. Some species do not enjoy company and are very territorial. It must be taken into account that the ecosystems where these fish live are very large and with a very large surface.

Even if you bring home the most gentle species, all fish need their space to be comfortable. When overcrowding occurs, not only is there the risk of the multiplication of toxic agents, but also because this alters their behavior. Fighting, biting, and cannibalism can happen because there are too many fish in one place. It is also recommended to use aquatic plants to create territorial barriers.

Let's bring an example. In a home aquarium 60 cm long, 30 cm wide and 30 cm deep, about 15 freshwater fish with a size of 5 cm can live peacefully and comfortably. However, when it comes to saltwater fish, everything changes. Freshwater specimens always need less water than the rest because the process by which they metabolize oxygen is slower. It should also be taken into account that the fish grow and the calculation must be made based on their size during their adult stage.

THE PROBLEM OF VERY SMALL AQUARIUMS

Currently you can find quite small urns, but these bring significant problems. 20 liter aquariums are often sold as a good option for beginners, but they are not. Normally, these aquariums have a capacity of 40 cm long, 20 wide and 20 deep. In these conditions there are many limits when it comes to choosing fish and many difficulties when maintaining stable and healthy water parameters. Undoubtedly, the variety of fish that these tanks house are very small and with a low biological activity that does not make the aquarium too dirty.

You also have to deal with the control of reproduction because the limit of inhabitants in these cases is quite strict and the limits cannot be exceeded. The difficulties increase when you think about the accessories, plants and elements that are introduced into the aquarium, since these take up space of clean water for the fish.

Although the idea of ​​buying a small tank to start with some fish seems the best, this often results in a deadly setback for the fish. As a rule, water parameters are easier to control when there is more water. Nitrates, nitrites, and other toxic agents are also less dangerous when diluted in greater amounts of water. For all these reasons it is that small aquariums are difficult to control and we reserve their use for specialized keepers.

OXYGEN

All two living things on earth need oxygen to live. In the case of fish, their respiration is a little different. While the oxygen that humans breathe we get from the air, fish get it from the water. In aquatic ecosystems, oxygen is diluted in water. Only a few exceptions can live without the oxygen in water. It is for this reason that the water in your aquarium must be sufficiently oxygenated for plants and fish to live.

In the case of aquariums with high temperatures, the solubility of gases is more complicated, so they usually have less oxygen than the fish need. However, keep in mind that too much oxygen can also affect the biochemical balance of the water. One of the fish that can live in low-temperature aquariums with highly oxygenated water is trout.

Trout can live well with a lot of oxygen because they swim in slow or fast flows. They also often jump to the surface to capture oxygen molecules from the atmosphere.

Although you can see that there are many wind currents in the atmosphere, you should keep in mind that the oxygen that is dissolved in the air is greater than that in the aquarium and this does not mean that it is enough oxygen that the fish need.

RESPIRATORY SYSTEM OF FISH

The gills are the organ by which fish obtain oxygen from the water. They are placed on both sides of the head. These are thin sheets with membranes that are full of folds. Due to this placement, they are in direct contact with water. The gill arch is what supports the gills, which are usually very fragile.

Because the aquarium is not a natural water stream, it is necessary to create oxygen diffusion. The daily activity of the fish helps to produce water bubbles that help this purpose, but it is not enough.

AQUARIUM OXYGENATORS

Respiration is a vital need for fish, and for this reason, oxygenating the aquarium well is essential so that the inhabitants can live and develop well. In most cases, artificial mechanisms are the best solutions to provide enough oxygen in the water. Oxygenators, pumps or filters work by moving water from the surface so that the air in the atmosphere is trapped in the lower water layers and can be the source of oxygen for fish and plants.

Compressors or oxygenators are these small devices with a plastic tube and a stone at the other end that produce bubbles in the water. Although this is one of the ways to oxygenate the aquarium, it is not oxygenation as such. The bubbles just break the flat surface of the water and move it around so that the oxygen is trapped in the water layers.

If the amount of bubbles that we see in the aquarium is small, it means that the water is moving little, so there is no opportunity for air to enter the water to oxygenate it. When the oxygen demand is high, and there is no alternate oxygenation system, there will be a deficit of oxygen in the water and the fish can suffocate.

Sponge filters are a good option in these cases because they do not absorb these bubbles that help oxygenate the aquarium. However, what you should be careful about is the sound of an oxygenator.

 

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A recurring problem with oxygenators is that they often come with a silent pump sign. However, one thing we have noticed is that many are not really quiet. Fish are animals very prone to stress because marine ecosystems are much quieter compared to the surface of the earth.

RECIRCULATION PUMPS

This was a slightly different type of aquarium oxygenator. It works completely submerged in water, thus capturing the water and then expelling it into the aquarium with a little more force. The expulsion causes a strong movement that manages to break the surfaces so that the air enters. It resembles a kind of pool in which you see some waves that trap oxygen.

These versions are more common in marine aquariums due to their ability to oxygenate the aquarium evenly. There are no dead or motionless zones left that could cause problems for corals. When corals are not ventilated enough, they have trouble filtering toxic substances from the water. You have to be especially careful with small fish such as guppies, rasboras or small prawns. These devices have a fairly large and powerful suction zone in which these little ones could get trapped.

FILTRATION OXYGENATION SYSTEM

In general, the filter can work or contribute to the oxygenation of the aquarium. If the aquarium filter has enough power it can move the volume of water. What should be taken into account is that it is not a filter that causes splashing outside the aquarium because it reduces the amount of water and produces an excess of unnecessary sounds.

OXYGENATING PLANTS

Plants are one of the most popular oxygenating solutions. They can oxygenate very well during the day and for this they need the appropriate amount of light according to the type of plants and CO2. Those that oxygenate the most and best are those that have a rapid growth. Elodea Najas, Vallisneria Spiralis, Hygrophila Polysperma and Limnophila Sessiliflora are some very common in aquariums and work very well for this purpose.

 

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It must be borne in mind that plants "breathe" at night, so they consume oxygen. In these cases, it is necessary to have some type of extra oxygen, at least during the hours of the night. This is to prevent the amount of oxygen from being insufficient at night, and the ones that most often suffer from this situation are the fish, as they cannot breathe well while they sleep.

WHAT ARE THE AQUARIUMS THAT DO NOT NEED OXYGENATION?

Red fish are in the popular imagination as one of the fish that do not need extra oxygenation. This is one of the most common mistakes because these fish are naturally cold water very well oxygenated. Although they can trap surface water and live with it, it is a poor livelihood to support them.

Betta fish are one of those few exceptions where you don't have to worry about oxygenating the aquarium. Due to the biological evolution of these fish, their natural ecosystems offer very precarious oxygen conditions. Thanks to their labyrinth organ, -which is responsible for their respiration- they are able to breathe the water found in the atmosphere. However, it must be remembered that this is an auxiliary system that helps keep them alive when they do not have enough oxygen in the water. This makes it necessary to keep them in an aquarium with the minimum oxygenation required for them and not force them to constantly jump to the surface to breathe.

In any case, a filter does well to oxygenate an aquarium. It is also a staple for keeping a clean aquarium. If you decide to do without a filter, the water changes will be more regular and you will have to find some way to oxygenate the aquarium.

THE BEST FRESHWATER FISH FOR MAINS

When we start an aquarium, especially if we are beginners, there are many factors that we must take into account. Fish are domestic animals that need specific care. The main problem with this is that most of us are not used to this type of care. In general, we meet other animals such as dogs or cats. However, there are freshwater fish that are very easy to care for and are the best option for those who are just starting out with their first aquarium.

NEON TETRA FISH

This is a specimen that belongs to the Carácidos family. They are related to piranhas and Cardinal Tetra, and like these, they are warm and sweet water. Some often confuse it with the Chinese Neon Fish, but the latter is from the cold water family of the Cyprinidae.

Although it is not so easy to reproduce in a home aquarium, it can be achieved. Despite this, it is very popular because it adapts very well to living with other fish. It has no demands on the quality of the water. This makes it a good choice as a first domestic fish.

An adult Neon fish is quite small and does not usually exceed 4 cm. The shape of its body is elongated and it has a round nose. It can be easily recognized by the blue or green stripe on the sides of its body. They also have a red spot in the ventral area.

In pet stores you can find varieties such as Red Neon Fish, Blue Neon Fish or Copper. In reality it is not something else, but the same Neon Fish that changes color according to the natural life conditions where it was born.

The strip on their body may disappear when they are in sewage as a form of defense against predators. The intensity of their colors can vary greatly depending on the type of substrate or the water background where they are.

The differences between the male and the female are not very noticeable. At first glance there are no obvious differences. The females are usually a little rounder and larger than the males, but nothing more.

The original regions of these fish are not clearly defined. However, areas of high localization and concentration have been found, such as the surroundings of Colombia and Brazil. Another area where they have been found are the populations of Paracheirodon Innesi, which is located a few hundred kilometers east of the Brazilian Amazon and the Purus River. This is the flow that flows into the Codajas.

They are usually found between the minor streams of the major rivers. They are usually acidic and soft waters that have a dark color due to the large amount of decomposing organic matter. Although this is not always their natural habitat; sometimes found in transparent river streams.

This is a very sociable fish that is comfortable when it has many companions. Groups of 8 or 10 can be added to make them feel in a more natural setting. You can add other Neon fish or other types of smaller or similar Characins. Cichlids can also live alongside a neon fish, as long as they are not aggressive or predatory.

Danio Rerio

The Danio Rerio is also known as Zebrafish and Zebrafish and belongs to the Cyprinidae family. It is recommended as a good option for those who start with aquariums because it can survive the typical mistakes of newbies in this care.

For those looking for fish that easily hatch, this is a very popular species. They are oviparous that reproduce easily because, among other things, they have a calm temperament and live well in communities with other fish.

They are small fish that do well in medium-sized aquariums. They do not usually exceed 5 cm in length and have golden or silver tones. They have dark blue stripes on the sides of their bodies. These stripes are what have earned it the popular name of zebrafish.

Sexual deformity is quite ambiguous while they are young, but when these fish reach adulthood, characteristic features are observed between both sexes. Adult females are larger and rounder. Over time, the skin color tends to fade in females.

During the spawning season, and when the female becomes pregnant, the males have a more intense coloration. The stripes on their bodies can vary depending on whether they are male or female. Males have blue or gold stripes, while females have blue or silver colors.

Danio Rerio is often confused with other Danios due to the difficulties in locating their native regions. Originally, it is believed that their first home was the waters of India, banks of the Ghats, Bangladesh and Bhutan. However, there is no concrete evidence that this is its origin.

Swift, but shallow waters can live well. The bottoms of these ecosystems are usually silty and with a lot of vegetation. After some recent research, it has been found that adults often live in small streams and rivers. During this time they look for calm waters and with little sun exposure. When the rainy season arrives they look for puddles and rice fields to spawn.

Ideally, combine a Danio Rerio community aquarium with other small cyprinids such as tetras, rainbow fish and catfish. This is a combination of calm and sociable fish that get along well with each other.

These are gregarious fish that enjoy living in communities. However, the number of 8 to 10 fish between males and females should not be exceeded. Providing a community environment between these fish is very important because they will feel calmer when seeing other small fish or of the same species around them.

GUPPY FISH

From the Poecilidae family, the Guppy fish are part of the Cyprinodontiformes. Within the large group of freshwater fish, it is very likely that this is the most famous. for several reasons.

Guppies are a very good option to begin to familiarize ourselves with the care that fish require at home. Their shape is very attractive because they have very bright colors, and the shape of their caudal tail has earned them great fame around the world. Another of their great strengths is that they reproduce easily.

This fish, like many other freshwater fish, was discovered in different geographic areas. Its scientific name is Poecilia Reticulata, but one of its most famous discoverers was John Lechemere Guppy. This is one of the scientists who implemented the breeding of this fish as a way to eradicate malaria, which is why it receives its trade name.

In this case, the differences between males and females are quite noticeable. Males are smaller than females and have much more striking and varied colors. They have also undergone a modification in the anal fin known as the gonopod. This is your sex organ and it is located on the back of the fish in a shape that resembles a shovel.

Due to all the genetic crosses that Guppys have undergone, we can see a male with pointed, rounded fins, like a deer crown, and the most popular and attractive, the fan-tailed Guppys.

The females are larger and can reach a size of up to 8 cm. They are thicker and with a much duller skin tone. In the species that have been reared in cauteverio some alterations can be seen, such as a caudal fin with more intense and brilliant colors.

Guppies are very popular with aquarium keepers, so there are a wide variety of shapes available. However, these constant genetic modifications have made them a little less resistant to diseases. Wild species are a little stronger against disease.

The waters of Central America and South America, along with the waters of the Caribbean, are the natural ecosystems of these fish. In areas with very high temperatures, they are used to kill mosquitoes that transmit malaria. Despite the fact that this is their original habitat, today they are distributed in many stores that sell them bred in captivity.

Guppies have a calm temperament and they can live with other fish that do not bite their fins. The Lemon Tetra or the Mollies can be good companions. It is necessary to bear in mind that males constantly chase females, so it is recommended to have 1 male for every 4 females.

COMMON CHARACTERISTICS OF WARM-WATER FISHES

Many fish in these types of waters can live together because they share the same natural habitat conditions. It is important that the pH, temperature and oxygen parameters are the same for everyone. They are also peaceful fish that do not tend to create too much conflict with each other. This as long as they are fish capable of living in a community, there are other very aggressive and territorial that must be kept without company.

It is important to note that lwarm-water fish are used to constant temperatures the vast majority of the year. They also tend to need longer and more stable sun cycles, so it is important to have a complete kit before bringing them home.

For any other question, or explore more about the world of aquariums and fish, you can visit our blog.

Other articles of interest may be:
How to Eliminate Aquarium Algae - Causes and Most Effective Treatments
Caridines and Neocaridines - File and Care Aquarium Prawns

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