Which fish to choose

Top 10 fish to start with

Deciding which fish to start first in your aquarium can be sudden, or it can be deliberate. Unfortunately, novice aquarists are often guided by the first impulse, completely not understanding the fish. And then, instead of joy and pleasure, they receive headache and problems. You need to choose fish wisely, because their life and your comfort depend on your choice. Before going to the store or the market, study all the available information about the fish that you like.

What kind of fish should not be bought for beginners, we examined here. And the top 10 unusual fish are here.

And in order to make it easier for you to navigate, we have compiled a list of the best aquarium fish for beginners and briefly described them. All of them are distinguished by unpretentiousness, tolerance for conditions in the aquarium, peaceful nature, livability and modest size. We hope it will help make your choice easier!

Guppy

Ancistrus

Swordsmen / molly / platies /

Danio rerio is a small (up to 5-6 cm), graceful fish. For its small size, peaceful disposition and unpretentiousness, it has earned great popularity in the aquarium hobby.

Since this schooling fish, it is better to keep at least 5-6 individuals. The aquarium can be planted with plants, but it is important that the zebrafish have free swimming space near the surface, as it is a very mobile fish. If you are going for a veil uniform, do not plant them with fish that can snap off their fins, such as the Sumatran barb. The aquarium should be closed as zebrafish can jump out of the water.

Omnivorous, they eat any kind of food - branded, live, frozen. It is better to feed them with flakes, since they pick up food from the surface of the water and collect flakes that do not sink for a long time. Breeding zebrafish is very easy, the female lays from 200 to 500 eggs at a time.

Corridors

Wedge-spotted rasbor

Acanthophthalmus

Lyalius

Cherry barbus

We select fish for an average aquarium

What fish live in a regular aquarium

Before you buy an aquarium, it is worth finding out which fish live in a regular aquarium. The purchase of an aquarium with an average volume of up to 150 liters opens up a lot of possibilities for its settlement. different kinds fish, including exotic ones. In such an aquarium, several variants of natural biotopes can be created. In this case, it is necessary to clearly divide the total volume of water into typical layers that create the most favorable living conditions for a particular type of aquarium fish. It is believed that if the mouth of the fish has a peculiar protrusion or is turned upwards, then such a breed prefers to live in the upper layer of water. Otherwise, the rock is bottom and populates the lower layers of the water. At correct selection For aquarium fish, all layers of water in the aquarium are evenly populated, giving the impression of a natural ecosystem.

The optimal number of fish for each layer is calculated based on the volume of the aquarium and the size of the aquarium fish. So, for fish up to 5 centimeters long, 1 liter of water is required. For larger fish sizes, add 2-3 liters each.

Depending on the characteristic features for some species of aquarium fish, it is necessary to provide for the settlement of calm and peace-loving fish into a separate layer of water, freeing up space for their more active counterparts.

Types of aquarium fish for the average aquarium

The most popular type of reservoir for aquariums up to 100-150 liters is the South American model. In this case, it is necessary to select small and medium-sized fish of the order of haracin (tetras, neons, thorns) or cichlids (blue cancer, scalar, parrots, discus).

It is also possible to colonize such combinations of fish as Sumatran barbs and pelvicachromis (parrots), blue akars, barbs and cockroach catfish, blue dolphins and iris.

The middle layer of water in the aquarium can be populated with spotted leopard ctenopoma. This shy fish has an interesting camouflage color and prefers a nocturnal lifestyle. Having calm nature, ctenopomas get along well with fish such as gourami, catfish and goldfish.

A medium-sized aquarium can be populated with a flock of 8-12 beauties of Congo fish. The scales of these fish are iridescent in color, so they look very impressive in a school. In the community of this type of aquarium fish, most representatives of the order of the haracinaceae, small catfish, viviparous fish and medium species of cichlids can live.

To populate the goldfish in the aquarium, you should reduce the stocking density of fish, without restricting them in movement. A medium aquarium is suitable for a pair of goldfish.

To create comfortable living conditions for various types of aquarium fish, it is necessary to determine the possible composition of the soil and plants in the aquarium and regularly keep it clean.

❶ How to choose fish :: aquarium fish itch :: Aquarium fish

A beautiful aquarium with unusual fish today can be found in many in public places... The desire for such beauty to be in your home is quite feasible.

If you did not have an aquarium with fish in your childhood, then before purchasing it, you need to collect all the information of interest. Which aquarium to choose and who to put in it.

Aquarium and accessories

Before buying fish, you need to decide on the amount that you are willing to spend. There is a wide range of aquariums. When choosing it, you need to know exactly where it will stand. Will he spoil the interior of the room? If there are other animals in the house - cats, dogs, parrots, then be sure to purchase an aquarium with a lid that already has lighting for the aquarium.
Modern aquariums are made of silicate and acrylic glass. Acrylic glass aquariums are less traumatic. The thickness of the glass directly depends on the height of the aquarium and its cost. Purchase an aquarium at pet stores, where you will be given a product warranty.
There are ready-made aquariums on sale with pedestals or stands, where you can remove all additional accessories. Their advantage is that it is a ready-made structure specially designed for this aquarium. After all, a filled aquarium has a lot of weight, a simple table may not support it.

Fish and their care

It is recommended for beginners in aquaristics to acquire unpretentious species. These are mosquitoes, swordtails, gourami, rerio, mocropods, guppies. These fish do not need a lot of oxygen. They belong to warm water species. Therefore, the temperature regime in the aquarium should range from 18 to 20 ° C.
More fastidious species include: high-fin mullies, cichlids. These fish should be in a lot of water (for 2 fish about 40 liters), the more plants the better. And don't forget about good aeration.
When buying pets for yourself, pay attention to their appearance. Deformed fins, inappropriate color, violation of the integrity of the integument indicate that the fish is unhealthy. Be careful and then you will protect yourself from buying a sick individual.
Do not settle peaceful species of fish with predators, small individuals with large ones. Use food suitable for this type of fish.
Use special feeders to feed the fish, this will help prevent contamination of the aquarium. If the water exudes a putrid smell, becomes cloudy or turns white, this is a sure sign that an urgent spring-cleaning... For control temperature regime get a thermometer. Some fish do not like changes in temperature, therefore, do not place them in water with different temperatures.

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Adult fish are beautiful, they already have well-formed fins and tail, bright saturated color. But nevertheless, it is better to buy young individuals, because there is no guarantee that mature fish will delight you for several more years, most likely, it does not have much left to live.

Fish for a small aquarium: how to choose :: aquarium fish for a small aquarium :: Aquarium fish

Not all residents of modern apartments can afford the maintenance and installation of a large aquarium, therefore, most often, a small aquarium is purchased. When choosing residents for such a small artificial reservoir, several rules must be followed.

The question “opened a pet store. Business is not going. What to do? "- 2 answers

A small aquarium should not be used a large number of fish. Purchase fish based on the assumption that one fish requires at least four liters of water. Considering that usually the volume of a small aquarium does not exceed thirty liters, you should not populate it with more than ten aquatic inhabitants. In addition, it is necessary to take into account not only the number, but also the size of the fish, because if rather large individuals grow out of the fry, they will be cramped and uncomfortable in a small volume of water. Consider such a factor as the features inherent in a particular breed of fish: it is convenient for some of them to live in the lower layer, for others - in the upper one. Some species of individuals are inactive, others, on the contrary, require continuous movement. Some fish are gregarious, others prefer solitude. When you populate a small aquarium with fish with conflicting qualities, you run the risk of disrupting their rhythm of life and creating chaos in the aquarium itself.

Which fish to choose

It is undesirable to inhabit a small aquarium with predatory fish species. Fish of delicate, rare, expensive and exotic breeds are not suitable for such a method of keeping, since in a small reservoir it will be difficult for you to maintain comfortable conditions for them, such fish often get sick and die.
Of the viviparous fish, the most unpretentious are the well-known guppies, they are distinguished by their mobility and very beautiful colors, their brilliant flock looks very impressive. Guppies breed well, so you need to make sure that the aquarium is not overcrowded with them.
It is quite possible to add bright swordsmen to guppies, they are also undemanding and will add bright red, black and green colors to your aquarium.
The cockerel fish is also very popular, known for its huge "rooster" tail and a variety of the most incredible colors.
Black mollies are a little more whimsical, you have to monitor the temperature and purity of the water, moreover, this fish prefers salt water.
Of the spawning fish, barbs, small zebrafish and veiled cardinals, which need an abundance of algae, are quite suitable for a small aquarium.
Also, tiny bright neons will not be superfluous, whose flocks will always enliven the aquarium and delight the eye.
All these breeds are distinguished by the small size of the fish and their high vitality. If you want to choose a larger fish, you can buy striped, sailboat-like, scalar or catfish, which, differing in their large size and bright colors, get along well with any other fish. In addition, these beautiful gold, green and speckled inhabitants of the bottom layer are the orderlies of the aquarium, cleaning the soil and walls from undigested food, dirt and algae plaque.
Thus, if you wish, you can populate even a small aquarium with a volume of ten to thirty liters with beautiful fish that will feel quite comfortable, successfully get along with each other and decorate your home.

Aquarium lamps and everything you need to know about them.

What are the best aquarium lamps

Metal halide luminaire with integrated blue lamps

Many sources point out that the best option- use fluorescent lamps. They shine well and are quite economical. They are connected by means of electronic ballast, as well as a special device - a choke.

Most hobbyists these days prefer special fluorescent lamps in combination with metal halides. In this case, they are placed on the front wall of the reservoir.

In addition, special aquarium fluorescent lamps of different wattage with warm or daylight white light are also used. The installation is carried out complete with special reflectors. With the right lighting, fish will exhibit a variety of colors, while corals will thrive.

Fluorescent lamps are economical, provide excellent lighting, and serve for a long time. As a disadvantage, it can be noted that they must be connected using a special device - an electronic ballast or choke.

Fluorescent lamps is the most popular type of lamp used in the hobbyist today.
These are low pressure gas discharge lamps. Inside them is a mixture of inert gas and mercury vapor, which gives an ultraviolet glow during an electric discharge. This glow is transformed into visible radiation, thanks to a layer of phosphor deposited on the inside of the bulb. It is the different compositions of the phosphors that give the different spectral range. And, for example, a three-layer phosphor and an ultraviolet protective film on a fluorescent lamp do not transmit the ultraviolet spectrum at all (everything that has a wavelength of less than 400 nm).

Fluorescent lamps are quite durable, but they must be replaced in the biotope with the same lamp (so that there are no abrupt changes in the spectrum and power of illumination) before their expiration date. It is recommended to replace such lamps at least once a year. And the average life of this lamp in an aquarium is 6-7 months. But you cannot change all the lamps at once: drastic changes in lighting power can adversely affect hydrophytes.

Beginners it is better for aquarists to take for a start unpretentious in the maintenance of fish. Over time, if the desire arises, move on to more demanding ones. This way you can avoid big disappointments in a pleasant hobby. Even species of fish that are not difficult to maintain need competent care, only you with them will be simpler and easier.
Always buy or take only those aquarium fish that you like, which pleasant to you personally. This applies to both species of fish and to specific individuals. Among the unpretentious and difficult to keep, there are many delicious, interesting and beautiful fish. The choice is large, you can always find it to your liking.
Better in the beginning familiarize with classification fish, read their characteristics. Understand habits, requirements and conditions content liked species. Do their lifestyle, breeding frequency, maintenance requirements, etc. suit you? This is not only pleasure and admiration. Aquarium fish need to be taken care of. Then you need to pick up compatible for keeping in one aquarium.
Having decided on the types of fish and the number of individuals for your aquarium, you can go buy. You need to buy healthy... Do not be too lazy to travel around several stores, bypass different sellers. And then go back to buy more trust, where the right fish are better. It's good to hold new fish in quarantine even if they look healthy on the outside.
If the aquarium is new, then at first you need to start the aquarium correctly and only in a few days you can buy and run first fish.

Aquarium fish are:

1. Freshwater, marine and fish that can live in brackish water.
Marine suitable for keeping in salted aquariums, sea ​​water. Freshwater- in fresh water, it is about them that will mainly be discussed below.
2. Preferred messages gregarious, single, paired or harem Lifestyle.
Depending on these preferences, you need to buy the necessary minimum quantity fish of this species in your aquarium.
3. Viviparous(the females do not spawn, but the fry that are already formed, ready for independent life) and spawning.
4. Tropical(minimum 18-20 ° C) and living v cold water (14-25 ° C).
5. Those who live mainly in upper layers of water, v middle layers of aquarium water and leading bottom Lifestyle.
6. Predators, varied eating, herbivorous.
Fry and comparatively more small fish most peaceful and calm fish (not obvious predators) are considered as food.
7. Nimble and movable, calm and slow(by temperament).
Agile can irritate calm and slow people. And large, but sluggish can nimble and aggressive small fins.
8. Very large, large, average, small and very small.
Large ones can exterminate, eat or simply kill clearly smaller ones.
9. Demanding a lot oxygen dissolved in water(must be kept in large aquariums), the average the amount and for which the amount of oxygen in water not very important.
The latter include those living in the bottom layers (catfish). And also labyrinth (cockerels, gourami), which are able to breathe oxygen from the atmosphere.
10. Territorial, aggressive and livable.
Some aggressive ones can only be kept alone or with larger species.
It is good for anyone to have plenty of hiding places in the aquarium made of plants, driftwood, rocks, coconut shells, etc.

Classification of aquarium fish with a description

Freshwater

→ Viviparous

Poeciliidae (Latin Poeciliidae)

About 20 genera and 140 species. The family contains many species of viviparous fishtooths. Unpretentious to feeding and keeping conditions, ease of reproduction.
Most species of Peciliaceae are brightly colored. A large number of new forms have been bred, differing in color, size and shape of the dorsal and caudal fins.

Pecilia (Xiphophorus, lat.Poecilia)

Swordsman (Xiphophorus helleri)

Mollies (Poecilia, or Mollienesia)

Guppy (Poecilia reticulata, or Lebistes reticulata)

→ Spawning

Labyrinth

Male Siamese Cockerel

Family of the order Perciformes. They are able to breathe atmospheric air through a special organ - a labyrinth.
Labyrinth fish are easy to maintain and care for, small. Males build a nest for eggs from air bubbles on the surface of the water.

Cockerel (Betta)

Gourami (Trichogaster)

Lyalius (Colisa lalia)

Macrapods (Macropodus)

Family Carp (Cyprinidae)

There are 275 genera, including more than 1500 species. Easy to maintain. Many species are gregarious. Many small in size. Nimble or calm, many are peaceful.

Goldfish (Carassius auratus)

Barbs

Danio Firefly

Danio

Cardinal (Tanichthys albonubes)

Rasbora

Labeo

Siamese seaweed (Crossocheilus siamensis) and Siamese flying fox (Siamese flying fox)

Common mustard (Rhodeus sericeus amarus)

Microrasbora

Family Kharacin, American tetras (Characidae)

Blue tetra

American tetras, neons - gregarious, small, peaceful (excl., Piranha), mostly brightly colored. Fish with characteristic dark spots and strokes that glow with reflected light.

Minor (Hyphessobrycon minor)

Ornatus (Phantom) (Hyphessobrycon)

Ternetia (Gymnocorymbus ternetzi)

Neon (lat.Paracheirodon)

Tetra

Piranha subfamily (Latin Serrasalminae)

Tetra Congo

Family Alestovy, or African tetras

Tetra Congo (Phenacogrammus interruptus)

Arnold's tetra (Arnoldichthus spilopterus)

Family Carptooth, Carptooth (Cyprinodontidae)

Afiosemion gardner

Brightly colored and unpretentious to the conditions of keeping and breeding, especially to the volume of the aquarium, they are excellent aquarium fish. They live in streams, rivers and lakes, live 2-3 years. Some species exist in drying up reservoirs and puddles and live only one season - 6-9 months.
It is interesting to get divorced. Species inhabiting permanent water bodies lay several eggs per day on benthic or floating plants near the surface. Species inhabiting dry bodies of water lay eggs in a soft substrate (most often peat). After the pond has dried out fish die, and caviar in peat it goes into a state of diapause, which in some species can be up to 18 months. At the onset of the rainy season and filling the reservoir with rainwater come out of caviar fully formed fry that swim and feed immediately. As an adaptation to the transience of the life cycle, representatives of these species become sexually mature at the age of 4-6 weeks.

Aphyosemion

Nothobranchius

Popondetta blue-eyed

Family Melanotheniaceae, Iris (Melanotaeniidae)

The family contains about 10 genera and is limited in distribution by fresh waters Australia and New Guinea.

Melanotaenia

Dwarf tetradon

Family Four-toothed or Pufferfish (Tetraodontidae)

In a moment of danger, they can swell like a ball to appear to the enemy "too large to devour."

Tetraodon

Family Cichlids or Cichlids (Cichlidae)

Akara

Apistogram

Astronotus , peacock eye (Astronotus ocellatus)

Discus (Symphysodon)

Scalar

Cichlids of African lakes

Family Toxotidae, genus Toxotes

They are distinguished by the ability to spray water onto land or into the air in order to knock down and subsequently eat the insects that they feed on.

Striped Archer (Toxotes jaculatrix)

Vyunov family group (Loaches, Loaches, Bocias, Balitorovs)

Very small scales... There are antennae. Most bottom fish, find food for themselves at the bottom.
In addition to breathing with gills, they are able to assimilate oxygen from water through the skin, as well as swallowing atmospheric air into the intestines (excl. Balitorovs).

Bociaceae (Botiidae)

Plucked (Cobitidae)

Pseudoskat Seville (Beaufortia leveretti)

Moth corridor

Family Armored or Callichthy catfish (Callichthyidae)

These catfish are able to breathe atmospheric air. Feed on the bottom, aquarium orderlies.
Peaceful and non-territorial. Easy to maintain and reproduce. Most are small (up to 6 cm).

Before you is a skillfully debugged and tastefully decorated aquarium. Behind the transparent glasses, pure amber water gurgles, shimmering, in the filter tubes. It refracts rays of light that enliven the miniature landscape: a sandy beach, a scattering of small pebbles, a rock-like terrace of large stones, a snag with intricate plexus, emerald thickets of plants. Elegant exotic fish, apparently, are happy with their lives in this amazing, warm, soft light-flooded world. An inexperienced observer has a burning desire to have the same living corner at home. Everything is so simple. If only I could get an aquarium, and there ...

But a beginner would know how deceiving this outward simplicity is and how many worries and griefs await him sometimes after the first imaginary successes, pleasant minutes. At first, everything will go very well. And then it may happen that the fish begin to die, the plants rot, the water deteriorates. An inexperienced hobbyist usually starts looking for answers in the wrong place. He is trying to find out how to care for this or that fish, for this or that plant, how to avoid this or that undesirable phenomenon separately, not realizing that the most important thing is to learn how to take care of the environment in which his pets live. Biologists call this environment the habitat, and it consists of separate, closely interconnected components.

The purpose of this book is to acquaint the reader with the features and properties of the main components of the habitat in an aquarium, to help understand the role of each component of the environment and teach how to manage it. For the attentive reader, the book will help to provide in general optimal conditions in a home reservoir, and, consequently, the well-being of the life of each of its inhabitants.

However, each aquarist, as he masters elementary skills, has a need to improve in his business, to go further. And then new questions arise: where to get food for aquarium pets; how to get fish to breed; how to learn how to create new varieties of ornamental fish?

Amateurs-aquarists are looking for meaningful answers to these and many other questions. Unfortunately, very little attention is paid to these basic problems in the literature. The traditional scheme of presenting information interferes - a little about everything. We decided to break this stereotype, forcing aquarists to mark time. In this book, an attempt is made to tell about the main thing, but in more detail. Each of us wrote about what he devoted many years of hard work. Therefore, the title of the book - "Secrets of Aquarium Fish Culture" - is not accidental, although the book itself, of course, does not contain any classified information. It's just that for new generations of aquarists, our experience can be as valuable as the secrets of longevity, beauty and youth.

Water is an amazing natural phenomenon, its unusual properties are still being studied by physicists, chemists, glaciologists, and representatives of other branches of science. But water is interesting not only in itself, but also as a habitat: in the hydrosphere of our planet (sea, fresh, underground waters), life is represented very widely.

The specific qualities of water as a habitat determine the formation of adaptive abilities in aquatic organisms (aquatic organisms), which enable them to live both in natural reservoirs and in their model - a home aquarium. For the correct management of life in an aquarium, a nature lover needs to know both the features of the aquatic habitat and the adaptive adaptations of aquatic organisms that have formed and live in this environment.

Gases dissolved in water

Water is a good solvent. In particular, it contains a large amount of gases. In an aquarium, water is enriched with gases through the surface as a result of the activity of aquatic organisms and with the help of special technical devices (aerators, filters). The transition of gases through the surface occurs due to molecular diffusion; when air bubbles pass through the filter and spray of the aerator, the same molecular diffusion operates.

Oxygen. The water is saturated with oxygen due to the photosynthetic activity of plants. In addition, oxygen enters the water from the atmosphere. To a greater extent, this gas is saturated with the upper layer of water in the aquarium. Therefore, to evenly distribute oxygen, it is necessary to maintain a constant vertical rotation of the water using an aerator or filter. This process of uniform oxygenation of all layers of water due to currents and waves on the surface is typical for rivers, streams, small creeks, from which most of the inhabitants of the aquarium originate.

The aquatic organisms that inhabit the aquarium differ in their attitude to the saturation of water with oxygen. Cyclops crustaceans are undemanding to this, but daphnia die at a rate of dissolved oxygen sufficient for cyclops. Tubifex and bloodworms, larvae of dragonflies and river mayflies, Luzhanka snails, melania and bivalve mollusks are also contrasting in their requirements for oxygen.

According to the oxygen demand, fish are usually conventionally divided into four groups:

1. Fish of cold and fast rivers, the so-called rheophilic: sturgeon, salmon, some species of catfish, goby, found in aquariums.

2. Fish living in rivers and backwaters, lakes, weak-flowing waters - most of the aquarium fish.

3. Fish of stagnant waters - from goldfish and its varieties to the Amur eleotris (firebrand), which is not very demanding on the oxygen content, or rotan.

4. Fish that have additional respiratory organs that allow them to capture atmospheric air.

For the correct keeping of most fish, it is necessary to observe a regime that satisfies the fish of the second group. At the same time, aquariums should have clean, no turbidity, water, a sufficient number of well-lit aquatic plants, constant mechanical stirring of water with an aerator and filtration.

The amount of oxygen consumed by fish is not stable. It should be borne in mind that in fish of the fourth group, additional respiratory organs are usually formed and begin to function not immediately, but 1-3 months after hatching from eggs. But even in the presence of such an organ, its owners have different oxygen needs. So, the macropod is much less demanding than the lalius.

A decrease in oxygen concentration affects the development of fish; their appetite usually does not decrease, but the biological direction of the assimilated food changes, less nutrients are absorbed, as a result, growth slows down. Considering this, with dense plantings of juveniles in rearing aquariums, it is necessary to ensure constant water exchange and aeration.

Carbon dioxide.

Plants and animals release carbon dioxide when they breathe. Fish - through the gills, but some, for example, loaches, and through the skin (up to 90% of the gas). Excessive accumulation of plants and fish increases the concentration of carbon dioxide in the water. Moreover, the aquarist usually notices the phenomenon of asphyxiation of fish, but long before that, an imperceptible at first glance change in the metabolism of fish occurs, their oppression, and the waste of previously stored reserves. In some fish, an increase in the concentration of carbon dioxide causes an increase in appetite, but food is not absorbed as needed, and an increase in feed consumption is accompanied by a slow depletion of their body.

This gas is removed from the water during the period of light photosynthetic activity of plants. Its amount decreases with increasing temperature and salinity of water. For most aquatic organisms, it is poisonous.

Lack of carbon dioxide in aquarium water is detrimental to aquatic plants. Most of them (Cryptocorynes, Echinodorus, etc.) belong to the coastal, sometimes flooded with water. In the atmosphere, such plants easily assimilate carbon dioxide in its pure form; Once immersed in water, they capture carbon dioxide from the water during photosynthesis. In the same way, however, some plants that have relatively recently become aquatic, such as aponogetons, living in rivers, where the supply of carbon dioxide is provided by the current, also "act". But in an aquarium with a small number of fish or in their absence (for example, the aquarist is only engaged in underwater gardening), the gas accumulated at night as a result of plant respiration is fully absorbed already in the first half of the day, and its intake as a result of daytime respiration of the same plants is completely insufficient for covering the photosynthetic needs of plants. Acute starvation occurs, plant growth gradually slows down, and then tissues begin to deteriorate. Aquatic plants that constantly live in stagnant water, such as elodea, are able to "extract" the missing carbon from complex compounds present in the water, and many botanical rarities extract it only from carbon dioxide. Therefore, dealing only with aquatic plants, the aquarist is forced to inhabit his underwater garden with a sufficient number of fish, although this complicates the care of underwater plantations, keeping the aquarium clean.

Hydrogen sulfide formed in aging aquarium systems as a result of life putrefactive bacteria and bacteria that reduce water sulfates. The role of the latter is insignificant, and the former is very high, especially if the remains of uneaten food accumulate near the bottom. Hydrogen sulfide is dangerous not only by itself, but also by its participation in chemical processes that reduce the concentration of oxygen in water.

Swamp gas (methane) is formed near the bottom, and in the ground, as a result of the decomposition of dead organisms, parts of plants. Both hydrogen sulfide and bog gas are poisonous to most aquatic organisms. They can be prevented by keeping the aquarium clean, correct mode its content, aeration and filtration.

Hydrochemical composition

Underground, river, tap waters have a very complex chemical composition... We meet pure water only in laboratory conditions. Current opinion about "clean" rainwater is devoid of any basis: it always contains chlorine, sodium, sulfate, calcium, ammonium. The amount of substances in rainwater, depending on the concentration of industrial emissions into the air, ranges from 0.8 to 489 mg / l. It makes no sense yet to talk about the "purity" of tap water. Depending on the concentration of industrial enterprises, river and lake waters have a lot of "extra" substances, despite the purification of water at waterworks.

In the water of reservoirs, many biological processes that change the chemical composition of water and saturate it with organic substances. The combination of all these substances determines the chemical composition of the water in the aquarium. But in different regions of the country it will, of course, be different.

Aquarium water contains various substances in ionic and molecular forms.

The main salt composition accounts for seven ions: calcium, magnesium, sodium, potassium, chlorides, hydrocarbonates and sulfates. In addition, water contains, to a greater or lesser extent, copper, manganese, iron, fluorine, iodine, boron, zinc and other elements. The degree of mineralization of different waters is also different, but usually does not exceed a gram per liter (in seawater it is much higher). To understand the biological role of all these components, it is important to know in what form they are in water and what chemical reactions occur in it.

Active reaction

The life of aquatic organisms in the aquatic habitat differs significantly from the life of living creatures in the air we are accustomed to. In the aquatic habitat, there are such limiting environmental factors that living beings in the air do not collide with. One of them is the active reaction of water. In seawater, the indicators of this reaction are quite stable, in fresh water they vary greatly depending on the season of the year and the time of day; they are different in different layers of water.

What is an active water reaction? The chemical formula of water, as you know, is H2O, its molecule consists of two hydrogen atoms and one oxygen. Part of the molecules

water under the influence of weak electricity breaks down into ions; the whole process is called dissociation. Salts, acids and alkalis dissolved in water decompose into the same ions. Water ions are designated H + (free hydrogen ions) and OH- (hydroxyl group). When the content of both in water is equal, they say that water has a neutral reaction. In such water, one molecule dissociates for every 10,000,000, and this figure can be expressed as ten to the seventh power of 10 -7 (and those and other ions, respectively, will be 10 -7 H + x 10 -7 OH- = 10 -14). As an indicator of the active reaction of water, the decimal logarithm of the ion indicator with the opposite sign will be. The neutral indicator will correspond (for the hydrogen ion H +, the number 7, called hydrogen index and denoted by the Latin letters pH.

The pH scale is a straight line from 0 to 14, where the already known pH 7 is strictly in the middle. To the left of it are acidic waters (slightly acidic - acidic - strongly acidic), to the right - alkaline (slightly alkaline-alkaline-strongly alkaline). Have sea ​​water pH 8, 1-8, 3; in fresh water, the fluctuations are stronger, but the whole scale in biochemistry is still not needed. Life in water is possible in the range of pH 3, 5-10, 5. Sometimes aquatic plants alkalinize (due to the enhanced process of photosynthesis) the surface layers to pH 11, while mobile hydrobionts go to the lower layers of the water, where this indicator is much lower. Mixing layers of water in natural reservoirs (a light breeze even in the most stagnant of them) relatively quickly equalizes the pH of different layers. In an aquarium without vertical rotation of the water (from aerators and filter), the destruction of plant tissue can begin from a high pH in the upper layers. In almost most cases, pH values ​​range from 6, 5-8, 5; in long-unclean, polluted aquariums, the bottom may have a pH of 5, 4.

The pH is extremely mobile, and the softer the water, the more. It depends on the temperature of the water, the life of plants (hence, on lighting), the degree of water mobility in the reservoir. In an aquarium, this indicator is constantly changing and can only be judged approximately. During the day, the pH can fluctuate by 2 units or more, so it is ridiculous to read in other aquarium manuals: "These fish need pH 6, 0-6, 3" - such accuracy can be obtained only in a small spawning jar without plants, but also in In this case, it cannot be guaranteed that the indicator measured, for example, in the morning, will remain at noon, in the evening and at night. In an aquarium with aquatic plants, this pH stability is completely ruled out.

Let's see how the pH in the aquarium water changes during the day. In the process of respiration of aquatic organisms, oxygen is absorbed, carbohydrates are oxidized, carbon dioxide is released, and energy is formed, which is used for life. In a chemical formula, this process will look like this:

C 6 H 12 O 6 + 6O 2 = 6CO 2 + 6H 2 O + chemical energy. Carbon dioxide entering the water causes acidification. This means that all aquatic organisms, with their respiration, contribute to a decrease in the pH value. This decrease is especially noticeable at night, when the plants do not absorb carbon dioxide. During the day, during the light phase of photosynthesis, the activity of carbon dioxide consumption by plants increases markedly. In the chemical formula, it looks like this: 6CO 2 + 6H 2 O + solar energy = C 6 H 12 O 6 + 60 2. Carbohydrates and free oxygen are formed. The absorption of CO2 by plants in good lighting can be so active that the intake of carbon dioxide exhaled by the same plants and other inhabitants of the aquarium does not compensate for the losses, which causes an increase in pH.

This means that at night the pH in the aquarium moves along the scale of indicators to the acidic side, and during the day - to the alkaline one. There are two ways to compensate for such shifts in pH:

1. Experienced aquarists do not change all the settled aquarium water, but only regularly replace part of it. Water topped up instead of evaporated prevents fluctuations in pH, but has a constant tendency to decrease this indicator. Where the water is hard enough, this problem practically does not exist.

2. Constantly carry out aeration of the aquarium: the supply of CO2 in the water is regularly replenished from the air bubbles supplied to the water.

The pH indicators change especially sharply during the day along the layers of water, if it is not constantly stirred. In the upper layers, during the intensive photosynthesis of plants, the pH can rise to 10-11, while at the bottom it will remain stable (say, about 6, 6), and in the middle layers it will fluctuate from 6, 5 (at night) to 7-8 ( during the day). Most aquatic organisms can still withstand daily fluctuations in pH of 1, 5-2 units, but fluctuations of 6, 5-11 during the day are dangerous for a living organism. At a pH of 10-11, fish sink into the lower layers, and the plants that gave rise to such alkalization of water will begin to collapse in the near-surface layers.

Fluctuations in the pH value also depend on the temperature of the water: with increasing temperature, it decreases. For example, if the indicator is measured at 0 ° C, then water should be considered neutral, not with pH 7, but with pH 7, 97 (almost 8), which means that water having a pH of 7 at 0 ° C will already be slightly acidic.

Depending on the ratio to the concentrations of hydrogen and hydroxyl ions, all aquatic organisms are subdivided into stenionic (withstanding minor vibrations) and euryionic (capable of tolerating large vibrations). In the hydrobiological literature, the first include those that can withstand fluctuations of up to 5-6 units. In aquarium practice, there are not so many of them, for example, from plants - elodea, hornwort. Cryptocorynes, aponogetones withstand smooth and regular fluctuations of 1-2 units, the same fluctuations are permissible for most fish, and species like discus are even more stenionic. For the inhabitants of the aquarium, there are certain, so-called pH barriers, going beyond which both to the left on the scale (towards the acidic side) and to the right (towards the alkaline side) is unacceptable. It is also unacceptable to move the inhabitants of the aquarium from one water to another with a difference in their pH values ​​of more than 0.8-1, since a shock may occur in fish, rapid or gradual destruction of plant tissues.

What happens to aquatic organisms when the pH value approaches the barrier values? Changes are difficult to grasp, but you need to be aware of them.

In plants, there is a phenomenon that aquarists, without going into its essence, called incompatibility. However, there are no practically incompatible plants in our aquariums, but there are plants with different pH barriers. For example, when the pH rises to 8, kabomba stops photosynthetic activity, vallisneria continues it until 10, and elodea up to 11. It is clear that the "starving" kabomba will first stop the growth of the apical stems and then shed the leaves. Gradually, in Vallisneria, the ends of the leaves near the surface will begin to collapse, the degree of alkalization of the upper layers of water by elodea for these two species will be an intolerable daily test. More complex plants are therefore difficult to maintain because their lower and upper pH barriers are slightly apart from each other - after all, in flowing waters, they do not have such pH jumps in their homeland as occur in aquariums with still water.

Lowering the pH of the water increases the appetite in fish. But there is no point in rejoicing at this: appetite is caused by a sharp decrease in the digestibility of food, a decrease in the use of nutrients for growth, an increase in energy costs. Some fish (for example, barbs) begin to scratch on the ground and stones, discognaths lose orientation AND die, a number of catfish die from dystrophy during active consumption of food. The oxygen uptake in the blood also worsens in fish, the respiration rate increases, but signs of suffocation appear. A decrease in the pH of the water for many tropical fish serves as an incentive for spawning - it is these numbers that are usually put down for rassor, haracinids and other species. But keeping them in acidified water is constantly impractical, especially to raise juveniles.

The most suitable water for most aquarium inhabitants should have a pH fluctuation of around 7. This is achieved mainly proper care behind the aquarium, the regular change of part of the water, the constant forced movement of it, the purity of the reservoir.

Redox potential of the aquatic environment

Life in an aquatic environment depends not only on its active reaction (pH value), but also on the redox potential, or redox potential. Redox potential stimulates or inhibits the growth and development of aquatic organisms. Speaking of gases dissolved in water, we mean molecular oxygen containing two atoms of this gas (it is molecular oxygen that is captured by blood hemoglobin during respiration of animals, assimilated during respiration and released in the light phase of photosynthesis by plants), when studying the role of redox potential - atomic oxygen.

The word redox is formed from two words - reduction (reduction) and oxidation (oxidation). Reduction will be the process of oxygen evolution or hydrogen absorption, oxidation - the process of oxygen absorption.

During oxidative or reduction reactions, the electrical potential of the oxidized or reduced substance changes: one substance, donating its electrons and charging positively, is oxidized, the other, acquiring electrons and charging negatively, is restored. The difference in electrical potential between them is the redox potential. In measurements (in electrochemistry), the magnitude of this difference is denoted as Eh and is expressed in millivolts. The higher the concentration of components capable of oxidation is to the concentration of components that can be reduced, the higher is the redox potential. Substances such as oxygen and chlorine tend to accept electrons and have a high electrical potential, therefore, not only oxygen, but also other substances (in particular, chlorine) can be an oxidizing agent, and substances such as hydrogen, on the contrary, willingly donate electrons and have low electrical potential. Oxygen has the greatest oxidizing ability, and hydrogen has the highest oxidizing ability, but between them there are other substances present in water and less intensively performing the role of either oxidizing agents or reducing agents.

Thus, both oxidative and recovery reactions not visible to the aquarist's eye. The oxidation processes immediately after the equipment of the indoor pond include inorganic substances... Populating the aquarium with plants and fish, other animals increases oxidative processes. They include dead parts of roots and leaves, animal excretions, mass appearance, and then death of bacteria, therefore, a newly built aquarium has a high redox potential. Then, mainly inorganic substances fall out of the range of oxidizable substances - their share in oxidation will be insignificant in the future. The amount of organic substances included in the oxidation processes is also stabilized (parts of plants damaged during planting do not die off, a constant amount of bacteria in the soil and filter is stabilized), and the redox potential decreases. It can increase dramatically as a result ecological disaster, which the habitat undergoes in the aquarium due to the inept actions of the amateur. These include an abrupt change in water, too much of the added tap water, which intensifies the death of plant parts and causes massive death of bacteria. The redox potential of water “bloom” sharply increases. In general, the indicator of this potential over the years of the existence of the aquarium tends to decrease - in an old aquarium with "old" water and silted soil, recovery processes are more active.

In biochemistry, in contrast to electrochemistry, the values ​​of the redox potential are expressed not in millivolts, but in conventional units of rH (reduktion Hydroqenii). There are special tables for converting the results measured with the device in millivolts into conventional units of rH. The scale of conventional units contains 42 divisions, 0 means pure hydrogen, 42 - pure oxygen... Naturally, near these! indicators life is impossible. In fresh water bodies, the habitable zone lies between 25 and 35 units. In an aquarium, it is less - between 26 and 32 units. Some plants withstand a slightly lower rH index (for example, for Cryptocorynes-25, 6), the highest level is tolerated by a heterantera - 32.

The relationship between pH and rH is closely related. Oxidative processes reduce the rate of active reaction of water (the higher the rH index, the lower the pH), reducing processes - they contribute to an increase in pH. In turn, the pH value affects the rH value. Thus, the rapid process of photosynthesis changes the value of rH in thickets of plants such as elodea and kabomba, which are capable of extracting CO2 from bicarbonates during photosynthesis: as a result, the OH- ion is released, alkalizing the water, and the rH index decreases; however, in other areas of the aquarium, it can remain unchanged. It should also be noted that the rH value is usually higher in the upper water layers, and lower in the lower ones. Since the pH values ​​fluctuate during the day, the rH value also changes. It also depends on the temperature of the water.

Redox notential readings are measured with sophisticated instruments with platinum electrodes that are not yet available to aquarists. In this case, the gas pressure, the concentration of the reduced form of hydrogen are determined.

How can one get an idea of ​​the magnitude of the redox potential, if there is practically nothing to determine it? Plants serve as a kind of indicators that allow one to indirectly judge the indicators of the redox potential. Thus, the growth of blue-green algae indicates a high rH; a high, albeit somewhat lower, rH index contributes to the rapid growth of green algae. Most aquarium flowering plants develop at 29-30 rH. Aponogetones bloom profusely at 30, 2-30, 6 rH, and already at 31 they shed their leaves. At the same indicator of redox potential, Echinodorus fall ill and stop growth, and above 31, aponogetones and Echinodorus lose rhizomes. Cryptocorynes, on the other hand, thrive at rH 26-29, a higher rate leads to their death, already at 29 they cease to reproduce vegetatively.

The redox potential, as mentioned above, is lower in the bottom water layers. At the surface of the soil, it is more than in the soil itself, if the sand in the aquarium is heavily caked. In fact, it is the soil that is the “weather kitchen”, which determines the total indicator of the redox potential in the aquarium: the more substances that tend to give off electrons accumulate in the soil, the more rH decreases. For the health of the aquarium, prolonging the well-being of the aquatic environment, it is necessary to maintain cleanliness in it, periodically rinse the soil.

Hardness of water

Freshwaters vary greatly in hardness. This indicator is determined by the presence of calcium and magnesium ions in water, and it does not matter in which compounds these substances are located. The amount of calcium and magnesium depends on the type of soil surrounding the reservoir, on the catchment area, season, weather, time of day. Naturally, water taken from reservoirs in different parts of the world differs significantly in hardness. V clear water of the Amazon tributary Rio Tapajos in one liter contains 1.48 mg of calcium ions, 0, 12 - magnesium. In the "black" water of Rio Negro - 1, 88 mg of calcium, but no magnesium. In the Amazon after the confluence of the main tributaries - 7, 76 and 0, 12, respectively. In the Neva, calcium ions are 8, 0 mg, in the Nile - 15, 8, in the Moscow River - 61, 5, in the Volga near Saratov - 80, 4 mg ...

Calcium and magnesium ions have a "+" sign and are designated as Ca ++, Mg ++; they are called cations and are associated with various anions bearing the “-” sign. If the cations are associated with carbonic acid anions, they speak of the carbonate hardness of water, if with the anions of chlorine, sulfur compounds, nitrogen, silicon, phosphorus, etc., they speak of non-carbonate hardness. The sum of all anions determines the total hardness. For example, Rio-Tapajos has a total hardness of 0, 3-0, 8, and a carbonate hardness of 0-0, 3, Rio-Negro-0, 1 and 0-0, 1, Amazon - 0, 6-1, 2 and 0, 2-0, 4, Neva - 0, 5 and 0, 5, Moskva River - 4, 2 and 4, 1, Volga - 5, 9 and 3, 5.

The total hardness of water is determined by the permanent and temporary, or removable. The latter can be reduced, for example by boiling water; it also fluctuates depending on the life of plants. With the elimination of temporary hardness, the total hardness of the water also decreases. In hydrochemistry, water hardness is expressed in milligram equivalents of calcium and magnesium; 1 mEq contains 20.04 mg / l Ca or 12.5 mg / l Mg. In biochemistry, this indicator is usually expressed in degrees. In Soviet aquarium literature, it is customary to express hardness in German degrees dH (from the word German hardness - Deutsche Harte), but in the books of other countries other degrees can also be found: one German degree is equal to 0.36 meq, or 1.78 ° French, 1, 25 ° English.

In hard waters containing calcium compounds, plants release carbon dioxide from carbonate substances during the day. This process takes place in the form of a complex chemical reaction, during which the calcium salt CaCO3 is formed, which precipitates out as needles of calcite. This sediment covers the leaves of those plants with a gray film that "know" how to obtain carbon dioxide in this way - elodea, rdestov, kabomba (not all aquarium aquatic plants have this ability). A decrease in the amount of carbonates in water leads to a decrease in its hardness and is called biogenic water softening. It is the higher, the better the plants are illuminated in the aquarium. Since the total depends on the carbonate, temporary, hardness, plants cause it to fluctuate during the day. In poor lighting conditions, as well as at night, part of the CaCO3 salt again becomes an ionic solution. Consequently, the hardness indicator is as variable as other water indicators. The hardness of water fluctuates especially sharply during its "blooming". Large fluctuations in time and total hardness can adversely affect the health of the aquarium inhabitants.

In soft water, the CaCO 5 salt reacts with carbon dioxide and significantly changes the pH value. Carbon dioxide dissolved in water actively interacts with water, forming carbonic acid, and bicarbonate ions are obtained from it, they dissociate and give carbonate ions, and at all stages of this complex reaction, water is enriched with hydrogen ions. In hard water, calcium and magnesium act as a buffer that inhibits these shifts, therefore, in cities where tap water is soft and temporary, or carbonate, the hardness is low, at night there can be deaths in the aquarium - the death of fish and other animals reacting to pH shifts. Cryptocorynes often experience physiological shock and shed their leaves. Where the water has a hardness of more than 6 ° dH, such troubles can be avoided. For the same reason, Cryptocorynes, Lagenanders and a number of aponogetones are better cultivated in water with a hardness of 6-8 ° dH than in the water in which they grow in nature (0.8-1.5 ° dH).

Aquatic plants that are sensitive enough to water hardness prefer slightly hard water, although there are exceptions. So, Madagascar aponogetons are latticed, baivianus grow in waters with a hardness of 0, 8-1, 2 ° dH, and in aquariums they die at a hardness of 4-5 °. Cryptocoryne ciliate, on the contrary, grows at a stiffness exceeding 20-30 °. In soft water, snail shells are destroyed, shrimp and crayfish do not tolerate molting well - these animals lack calcium. Most aquarium fish live normally at 3-15 ° hardness. But here, too, we encounter deviations. Viviparous fish need water with a hardness of 10-153 dH, haracinids prefer 3-6 °, cichlids of Lake Malawi - 14-20 °. Some gobies from the rivers Central Asia they die very quickly in soft water.

In our country natural waters it is customary to subdivide into very soft (2-4 °), soft (4-11 °), medium hard (11-22 °), hard (22-34 °) and very hard (more than 34 ° dH).

Nitrogen and its compounds

Aquarists should pay attention to some aspects of the nitrogen cycle that occurs in water, since, on the one hand, the compounds of this gas are extremely needed by plants and other aquatic organisms, and on the other, they can have strong toxic effects, such as ammonium and nitrites. Ammonium in the aquarium is formed as a result of rotting organic residues (food, plant parts, fish carcasses) containing organic nitrogen compounds.

Actually, the process of decay is called ammonification. During this process, complex nitrogen-containing substances are converted into ammonia and water, and ammonia can be absorbed as a mineral by plants. However, a number of authors consider ammonia (NH 3) also toxic when it accumulates in large quantities. In the literature, ammonium (also a mineral substance) is understood as the sum of ammonium ions (NH 4) and free ammonia.

Most fish release ammonium through the gills, on the surface of which ammonium ions are exchanged for sodium ions necessary for the cells of the fish body.

When the aquarium is relocated, the water is not regularly changed, animals cannot get rid of the excess ammonium, which constantly accumulates in the body during nitrogen metabolism. Ammonium and ammonia ions penetrate in excess through membranes and cause poisoning of cells, then of the whole organism. At a high pH, ​​ammonia is more toxic, therefore, a shift in this indicator in alkaline side should not be allowed. With a low oxygen content, both ammonium components become even more toxic, which means that aeration and filtration of water is constantly needed. When in an overcrowded aquarium with non-replaceable water, the ammonium content increases as a result of metabolic processes and excretions, the fish breathing quickens even with aeration, but the uptake of oxygen molecules by the blood drops sharply. A decrease in oxygen in the blood causes a violation of the acid-base balance in the body.

Nitrite (NO 2) also reduces the ability of blood hemoglobin to capture and carry oxygen. Nitrites are formed during the oxidation of ammonia salts to nitric acid salts. The process ends with the formation of nitrates (NO 3), and nitrites are, as it were, an intermediate product. Their presence even in small quantities in the water of a freshwater aquarium is quite dangerous.

Nitrates are not so toxic, but fish living in water with a high concentration of this nitrogen compound gradually acquire a pale color of the gills. The causes and consequences of this phenomenon have not yet been established. There is evidence that a long stay of fish in a solution with a high concentration of nitrates causes impaired coordination of movements, scratching, decreased activity, and shortness of breath.

To reduce the toxicity of ammonia, four rules should be followed: constant aeration, cleanliness in the aquarium, regular water changes, moderate colonization by plants and animals. To limit the content of nitrates, regular water changes and colonization with plants are necessary, and the excess must be removed.

Peaceful fish are not boring at all - there are many species for safe cohabitation, all of which are also beautiful and interesting, in bright colors. In order for the settlement to succeed, it is necessary to take into account the water conditions in which the fish can live, their lifestyle and behavior patterns. Consider the most popular peace-loving fish.

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Schooling fish

Neon tetra (Paracheirodon innesi)

The neon tetra is a wonderful pet for the aquarium, which can be settled in a tropical reservoir. Suitable for beginners - aquarists - she has a calm disposition and unpretentious maintenance requirements. Will stand out against the green aquarium plants. It is necessary to keep neon tetras in aquariums with a volume of 50-100 liters (for 5-8 fish). In the early days, the settlements will perfectly fit into the underwater ecosystem.

Iriatherina werneri

Although the males of these fish of the Melanothenium family can fight with each other, in fact they are peaceful fish. They are often victims of other fish that like to pluck their long fins, so it is better to settle for the same peace-loving species. When kept in a good and spacious aquarium with a volume of 50-60 liters in a group of at least 6 individuals, they will demonstrate interesting behavior and kind disposition towards their neighbors.

See what Iriaterina Werner looks like.

Carnegiella marble (Carnegiella strigata)

Carnegielle Marble is an excellent choice for a 60-100 liter aquarium. They float in the upper layer of the aquarium. They have a very interesting appearance: their wedge-shaped abdomen and variegated color immediately attracts the eye. They are calm and shy, they can leave other fish alone. Aquarium fish are kept in groups, it is recommended to settle a school of 6 individuals at least. The flock prefers to swim in the upper layers of the water, without disturbing the benthic fish with a peaceful disposition. However, the aquarium should have a lid to prevent fish from jumping out of it. Sometimes you can hear bangs on the cover - it means that it is frolicking or requires attention to itself.

Catfish

Fish twig, or Farlovella catfish (Farlowella vittata)

Farlovella catfish is an excellent choice for hobbyists who want to take care of the cleanliness of their home aquarium. These herbivorous catfish will definitely not hunt the fry of other fish, and even small fish. They prefer calm, peaceful aquariums, where there is no place for hostility. They do not take food away from others, but eat up its leftovers.

They grow up to 15 cm in size, so they should be settled in spacious aquariums with a volume of at least 120 liters. Sensitive to the parameters of the aquatic environment. Twig fish are the best algae eaters. Their maintenance requires constant feeding with plant food - zucchini and plates of algae, otherwise they will eat aquatic plants. Compatible with peaceful fish swimming in the upper water layers.

Otocinclus affinis

One of the calmest species of catfish, it also loves to eat algae. They look like charming fish, they are distinguished by a peaceful disposition and a slow swimming style. An aquarium with a volume of 50 liters or more is enough for settling. It is advisable to settle 6 fish at once, since the catfish are shy and timid.

Also requires availability enough shelters in the form of grottoes, caves and snags. Their fragile body is sensitive to water quality, so regular water renewal is imperative. Can be settled with small fish (no more than 5 cm) and slow ones, swimming in the middle and upper layers of the reservoir.

Catfish panda (Corydoras Panda)

Panda corridor - small fish of the Armored catfish family. They can live in an aquarium with a volume of 50-100 liters. They are bottom fish that prefer rectangular aquariums with a sandy substrate. Like other aquarium catfish, you should live in a group of 5-7 fish to feel safe.

They are contactable, friendly with each other, sometimes they arrange games and catch-ups, without causing damage to each other. Sometimes they exhibit hyperactive behavior. The best neighbors for them are other small corridors, and small fish up to 5 cm in size, which do not show an aggressive disposition and swim in the upper and middle layers of the water. It is important that the catfish get the food they collect from the bottom.

Viviparous species with a peaceful character

Mollies

Mollies: many types of mollies in captivity grow up to 5-10 cm. Their nature is completely harmless, therefore they are compatible with peaceful and medium-sized fish. It is not recommended to settle for predatory, active and aggressive species... They perfectly exist next to other viviparous fish: guppies, swordtails, platies.

Guppy

Small aquarium fish, males are smaller than females, the length of aquarium species is 4-5 cm. Peaceful creatures, do not touch neighbors. However, large and predatory fish can offend them. Cannot be kept with aquarium sharks, swordfish, giant gouras, pangasius. It is also not recommended to settle barbs and thorns with them, which like to cut off the fins of beautiful fish.

They take root well with neons, rasbora, cardinals, speckled catfish, tarakatums. A small school of 5 fish should be settled in one tank, in such a quantity they will be comfortable and safe. For such a number of fish, a 20-50-liter aquarium is enough.

Swordsmen

Swordsmen: unpretentious, bright and beautiful representatives water world, characterized by peaceful behavior. However, you should know that male swordtails show aggression towards each other, each of them has its own, individual disposition. Males are slightly smaller than females - 8-10 cm. Aggression is promoted by cramped aquariums, in which there are either no plants, or very few of them. No more than 2 males can be kept in one aquarium, this will lead to fights. They live well with other fish, both viviparous and spawning. It is not recommended to settle with goldfish. Their ideal neighbors:

• Pecilia;
• Guppy;
• Mollies;
• Gourami;
• Neons;
• Scalars;
• Iris.

See how to keep swordsmen.

However, this is not the whole list of peaceful fish. The next ones take root mainly with small viviparous species and medium-sized catfish.

Other peaceful species

Gourami - endemic South-East Asia... Love calm warm water... In the general nursery, barbs can terrorize them, since the movements of the fish are slow and unhurried. Plant live plants in groups to give the fish a place to hide. Compatible with, swordtails, mollies, iris, discus.

South American scalars - poorly coexist with guppies and neons, perceiving the latter for food. They are kept in the same conditions as large cichlids. It is advisable to settle alone or at once two adults that grew up together. Neighbors-swordsmen can resist them due to their dexterous disposition.

Iris are aquarium fish of bright colors, which in wildlife attract predators. Incompatible with koi carps, cichlids, goldfish, astronotus. Compatible with scalars, gourami, corridors, zebrafish, guppies, mollies, rasbora, battles.

In this section, you can get acquainted with various types of aquarium fish and their descriptions, find out the names, conditions of keeping, behavior and compatibility with other inhabitants, how and what to feed, the difference and recommendations for breeding them. Ornamental fish that are kept in aquariums are aquarium fish with bright and varied colors, body shapes and sizes. In nature, each body of water is a habitat for representatives of the "fish kingdom", and thanks to their diversity, aquarists have the opportunity to keep a variety of tropical fish in their home aquariums. For the convenience of finding information, the section is divided into categories by types of Aquarium fish, such as "Catfish", "Barbs", "Goldfish" and others. Here, on the pages of interesting, illustrated and informative articles of the "Aquarium Fish" section, you will find a lot of useful information, selected especially for people who are keen on or taking their first steps in such an exciting activity as Aquarium.

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Cockerels of this genus are represented by quite diverse species - Betta picta, Betta taeniata, Betta smaragdina, Betta unimaculata, Dwarf cockerel (Betta imbeIIis), P ...

Piranha- Known as an insatiable predator, capable of quickly ripping flesh from bone and dangerous to any animal entering its waters, it is the most famous freshwater fish in the world. As a result, the demonstration of this "bloodthirsty" creature ...

Or Raphael's Striped Catfish, makes sounds similar to creaking or clicking, for which he received the nickname "talking catfish." This vibrant and popular species is often regarded as the perfect beginner catfish, hardy and tolerant of a wide range conditions ...

Plecostomus an inhabitant of the bottom water layers, is active mainly at night. Compatible with any peaceful tropical fish living in the middle and upper water horizons, does not like competitors claiming bottom territory ...

SenegalesePolypterus Is one of the most unusual freshwater fish. It is not for nothing that it is called a dragon fish, its relict appearance, which evokes thoughts of the era of dinosaurs, is simply mesmerizing. Can live in captivity for up to 10 years, very hardy ...

Popondetta furkata- bright and very playful fish feel great in a flock of 6 paired individuals. She is quite peaceful and gets along well with the same peaceful neighbors, likes to hide, so you need to have a lot in the aquarium ...

Iris Turquoise- one of the most beautiful representatives of the genus. A bright, peaceful, unpretentious fish, spending most of the time in motion. Feels as comfortable as possible in elongated, well-lit aquariums ...

Boesman's iris- relatively recently appeared in decorative aquarium hobby, but has already managed to firmly establish itself in the hearts of amateurs. Like all melanothenia, the fish is unpretentious, peaceful, active, but most importantly very beautiful, easily adaptable ...

Cockerels differ in the shape of the fins and in color. And all this splendor belongs to one species of cockerels - Betta splendens. Maybe various combination forms of fins in one species of fish - halfmun and crown-tailed, short or long ...

Rasbora brigitta- one of the smallest representatives of the carp family. Nevertheless, the flock of these dwarf rasbors, due to their bright color, will not be lost even in a relatively large aquarium. Peaceful and schooling fish. Better keep a group ...