Cichlidarium.
The interesting behavior of fish during various moments of their lives, related to mating games, courtship, defense of their territory, and feeding methods, makes Cichlidae welcome guests in any freshwater aquarium. Often, a Cichlidae aquarium is called a cichlidarium, but this is a narrower interpretation, since actually not only Cichlidae can live in such an aquarium, but also any large fish.
An aquarium for Cichlidae can be of two types: the first is for keeping Cichlidae inhabiting the warm waters of South America (some African Cichlidae may also be kept here), and the second is for keeping Cichlidae from the African lakes Malawi (Nyasa) and Tanganyika, as well as Central America.
When choosing an aquarium, you must first determine its size and shape. In addition to the size of the Cichlidae, you should consider the future species composition of the aquarium, the temperament of the fish you have chosen, their lifestyle, character, and so on. The most suitable shape is a “trough” — an aquarium with the maximum bottom area. Experience shows that for keeping a small collection (3-4 species) of even small lake Cichlidae, an aquarium with a volume of at least 150 liters and a length of at least 80 cm is required, though it must be understood that only small fish (up to 15 cm) can be kept in such an aquarium. This kind of aquarium allows territory to be divided between males.
The currently popular volume of 240 liters will already allow you to vary the composition of the aquarium, and there are mass options for an interesting composition of your aquarium. Smaller water bodies can only be used as temporary homes or as breeding facilities. For keeping Cichlidae, the more space in the aquarium, the better. To make them behave as close to natural behavior as possible and reach the size and coloration they have in the wild, a large aquarium is necessary. Even relatively peaceful fish become aggressive in a small aquarium.
You should not write off small by modern standards 100-liter vessels, where, for example, a couple of species of shell-dwelling cichlids and several *Julidochromis* will get along wonderfully. This aquarium is also good for keeping a pair of adult *Altolamprologus* — it is convenient to observe “unhurried” fish in this aquarium. A pair of adult *Neolamprologus brichardi* or large *Julidochromis* will also not get lost in this volume. The aquarium will look quite full, as the fish often produce differently sized fry.
In “desktop” aquariums with a volume of 25-30 liters, a pair of shell-dwelling *Lamprologus*, known for their miniature size, can live wonderfully. Here, they also bring forth their small offspring. In such an aquarium, you should approach the selection of equipment and decorative materials with particular care.
A mandatory condition for introducing fish into the aquarium is at least 15-20 liters per individual. Small Cichlidae from Lake Tanganyika are perhaps an exception. However, there are precedents when even in a three-ton aquarium, some small fish, especially large representatives of *Cichlasoma*, *Amphilophus citrinellus*, and *Crenicichla*, have such an unbearable character that, literally speaking, they do not allow all other inhabitants, including conspecifics of the opposite sex, to coexist normally. There is only one way out — to keep such fish individually in small aquariums. The main thing is that its width allows the fish to easily turn around.
*Astronotus* require an aquarium of at least 200 liters. They need to be kept in monoculture. *Astronotus* is unpretentious, lives and spawns in medium-hardness water, quickly adapts to a new environment, and rarely gets sick. Pairing them is a long and difficult process.
When creating large collections of Cichlidae, primary attention should be paid to community selection. In a general aquarium, carnivorous and herbivorous fish should not be combined, because the carnivorous ones will constantly starve, while the “vegetarians”, as a rule, are more temperamental and will suffer from protein poisoning, digestive disorders, and other diseases. It is undesirable to place Cichlidae requiring alkaline and acidic water reactions in the same aquarium, especially if their temperature requirements also differ (for example, *Julidochromis* and *Apistogramma*).
Often, active males of a number of Malawi Cichlidae, *Tropheus*, etc., literally terrorize other inhabitants of the aquarium, preventing them from feeding and developing normally. Often this is an individual trait of a specimen. It is better to remove such fish from the aquarium or completely exclude keeping super-temperamental species in this particular community.
Depending on their habitats, Malawi Cichlidae are subdivided into Mbuna, which are rock-dwelling inhabitants, and Utaka, which inhabit the water column and open sandy areas. It is not recommended to house representatives of these two different types together because their diet and behavior are different. Small species like *Apistogramma*, *Nannacara*, and *Pelvicachromis* can quite well be kept in a sufficiently spacious regular aquarium with other decorative fish.
Keep in mind that these species are predators, so careful selection of neighbors is required (they must be either sufficiently agile or equally large) and especially of pairs. To avoid conflicts between males, you should select 1 male and 1-3 females of each species. The most sensible approach is to purchase several young Cichlidae and wait for a pair to form from them. *Synodontis*, *Pterygoplichthys*, and other large catfish get along with them in the same water body. *Piaractus*, large *Metynnis*, *Barbus*, *Balantiocheilos melanopterus*, and *Melanotaenia* look good here.
The presence of these fish in the aquarium not only decorates the water body, but also helps relieve the stress to which lonely swimming Cichlidae are subject. Another option could be a combination of different knifefish (*Apteronotus*, *Notopterus*), Blood Parrots, and *Arowana*. In captivity, timid and cautious Cichlidae settle in better in the company of schooling, sociable fish of other families. The presence of unperturbed, cheerfully darting neighbors calms Cichlidae and fully allows them to show their habits.
Very often, joint maintenance of large species of loaches (*Chromobotia*, *Yasuhikotakia*, *Syncrossus*) with large and medium Cichlidae is proposed. These are completely different species of fish from different regions. Loaches originate from fast rivers and streams in Asia. Water flows there are quite strong, and water parameters are soft and acidic. On the other hand, lakes in Africa have a very hard, alkaline composition, which can have serious consequences for their osmoregulatory systems. Many Cichlidae are herbivorous, while the natural diet of loaches mainly consists of “fleshy” products, such as insect larvae, worms, and crustaceans.
Cichlidae are known to be aggressive and should not be placed with other fish species; loaches will be forced to live with them within the aquarium and have no real way out. When Cichlidae reach sexual maturity, the level of aggression increases, and sensitive species such as loaches are persecuted and will constantly be on the verge of survival. Loaches need hiding places, and Cichlidae do too; besides, they dig up the substrate, leaving loaches with no living space. Loaches may temporarily survive in such conditions, but their health will suffer, and they will not show their interesting behavior and coloration.
More often, such an aquarium is populated with fish that inhabit rocky biotopes in nature. Fish inhabiting the African lakes Malawi and Tanganyika are very popular in such aquariums. Fish are attractive not only for the variety of color forms, but also for their behavioral features, with clearly expressed territoriality, reproductive features, and offspring care.
Representatives of Mbuna are small, territorial, and quite aggressive fish. Malawi fish belonging to Utaka are much larger and more “tolerant”. Most of them, with a normal full diet, do not touch underwater flora at all, except perhaps soft-leaved long-stemmed plants, which quite allows keeping these Cichlidae both in a mixed aquarium and in a tank with live plants. Representatives of the Utaka group are quite sociable. The main thing is that neighbors should not be sluggish and should not fit entirely into their mouths.
Cichlid Aquarium Design.
There may be no substrate in the aquarium at all; this is the most convenient option (there is no need for cleaning, no need to siphon it). However, the option without substrate is not always aesthetic. If substrate is used, fine-grained (2-4 mm), medium-grained (4-6 mm), and pebbles are applied. Natural substrate of dark tones and large fractions is preferred. Furthermore, there are almost no restrictions on substrate fraction sizes here.
Different substrates are used depending on the needs of a particular species, its size, and properties. Shell-dwelling and many small *Lamprologus* need to be provided with the finest sand (0.5-1 mm). Sand of a similar fraction is absolutely necessary for Cichlidae of the genera *Enantiopus*, *Xenotilapia*, and others that sift it through their gill apparatus, thereby extracting small invertebrates for themselves.
Larger sand (2-3 mm) is great for medium-sized *Lamprologus*. This substrate retains organic residues better than others and is convenient for cleaning. Sand is placed in the aquarium in a layer of 3-5 cm, no more than 5-6 cm, so that plants can be planted there and it will act as a biofilter. For Cichlidae of the species *Cyathopharynx*, *Enantiopus*, *Ophthalmotilapia*, more sand should be added — 7-8 cm; these fish species create large craters 40-50 cm in diameter during spawning.
The color of your substrate will directly affect the coloration and well-being of your pets. The currently fashionable frankly white sand is not very suitable for most Cichlidae. Most species (with rare exceptions) look much paler on it than they actually could. Gray rounded sand of the same fraction of natural origin will perfectly emphasize the bright, diverse attire of your fish. If you want to add substrate, remember that stones should be placed in the aquarium first, and then the substrate. And whatever relief you give to the substrate, large fish, even if they do not belong to “diggers”, will still level it out within 1-2 weeks.
Stones are a rather significant element in aquarium decoration. Stones placed in the aquarium enliven the underwater landscape and make it more natural. The shape of the stone depends on the created landscape of the aquarium, as well as on the purposes it will serve. Stones of richer, concentrated shades (dark brown, dark green, bronze) are used. Rock formations form the basis of the design. When buying stones, check them for sharp edges; such stones are undesirable in the aquarium because Cichlidae are very active fish and can hurt themselves. Good natural stones are Kenyan rock, jasper, and serpentine, which simultaneously maintain an alkaline environment in the aquarium.
Calccareous tufa is a very rough and fragile limestone. It is porous and light; it can be drilled, and various built-in shelters and passages can be made in the stone. Large structures can be built from it, resting against the back glass of the aquarium without overloading it. It needs to be rinsed under running water once a month. When decorating the aquarium, do not clutter it with stones; it will be difficult to catch fish in such an aquarium later, and attempts to dismantle the pile of stones may lead to an accidentally dropped boulder breaking the bottom of the aquarium.
The aquarium should abound with shelters and caves so that weaker individuals or females can find refuge from excessively active, dominating males or more aggressive conspecifics. It is not necessary to create foregrounds and backgrounds in it. Rock formations form the basis of the design, and a large number of bulky, heavy decorations (large stones, driftwood) of richer, concentrated shades (dark brown, dark green, bronze) are used. But at the same time, the aquarium is less loaded, with more free space and open areas.
It is desirable that stones and substrate consist of limestone rocks. With the help of such stones, the landscape of the coastal zone of the water body is created with an abundance of caves and grottos, through-passages, and depressions. Multi-story structures with corridors of various sizes should serve as a simulation of rocks in the aquarium so that a small fish hiding in them becomes inaccessible to larger neighbors.
Usually, the rock in the aquarium is constructed in the form of a background, or 2-3 separately rising rock massifs, while leaving sufficient operating space for actively swimming fish. You can build a pile of stones right up to the water surface, or place them in groups on the bottom, decorated with broad-leaved plants. Both methods can be used. Large flat stones can be used for terracing the substrate. And so that the fish cannot undermine and destroy such “rocks”, they must be installed directly on the bottom of the aquarium. Stones should not have sharp angles, as fish can scratch themselves on them.
Driftwood can be arranged in two ways. If they are branchy, they are placed vertically — with thin branches in the substrate, so that the upper cut goes beyond the water surface. Compact, chopped driftwood can be laid on the bottom, following the principle of creating a composition center, when an attractive horizontal structure is created from driftwood, arranged with nearby stones and bushes of large live or synthetic plants. In a littoral spirit, the background should also be chosen: ceramic and relief plastic internal backgrounds, monochrome or with a rocky landscape — flat external ones.
Another rule for decorating the aquarium is maintaining scale. The sizes of all decorations and fish must correspond both to each other and to the aquarium. Since we are dealing with large and, as a rule, heavy decoration elements, the issue of their reliable fastening must be put at the forefront: most of the decorations will have to be glued with silicone. This is especially true for prefabricated structures made of separate stones.
If you plan to stock the aquarium with large Cichlidae, which tolerate any aquarium rearrangements very painfully, plan and think everything through properly before starting to decorate the aquarium. It will be very problematic to change the composition later. Cichlidae are very sensitive to changes inside the aquarium because they are territorial. Every stone and plant is their property or territory boundary. Shelters must be combined with free swimming spaces.
Live plants, if used (very редко), are only hard-leaved ones with large leaves and a powerful root system, and even then, mostly in pots. Unfortunately, most plants grow poorly in the conditions required for African Cichlidae. Live plants for the aquarium require constant qualified care and a special set of necessary aquarium equipment, various additives, and fertilizers.
It is best to use artificial plants in such a water body, because if live ones survive here, they will look perpetually tattered. And do not be afraid of artificial plants. After all, greenery noticeably enlivens the landscape, adds contrast, and removes depressing gloom. Lighting in the aquarium should not be too bright, but rather subdued.
If you categorically reject the use of artificial plants, you can also use natural ones. Suitable ones include powerful, broad-leaved *Echinodorus* planted in pots, some *Cryptocoryne*, *Vallisneria*, *Anubias*, and Java fern. A pot deepened into the substrate up to the neck must be additionally fixed on top with several fairly heavy stones. Any plants — both artificial and live — are placed in separate clumps among stones and driftwood.
The synthetic bush must necessarily be equipped with a “saucer” — a specially shaped base that allows the product to be reliably fixed in the substrate. Moreover, this “saucer” should preferably not just be buried, but filled with silicone or epoxy glue and weighted down with stones. This allows the synthetic bush to be more securely “rooted” in the substrate, and even if a fish pulls out the plant, it at least will not float up and the aquarium will not lose its decorative appeal.
In an aquarium with inhabitants from Malawi and Tanganyika, a specific lighting regime must be strictly observed. Lighting in the aquarium should not be too bright, but rather subdued. It should be taken into account that daylight rays falling from the front and sides create areas with moving shadow. Fish do not like this and become so timid that they spend the whole day in shelters, making the aquarium look empty.
Therefore, it is necessary to provide sufficient illumination of the water body with artificial light sources. The duration and intensity of illumination depend mainly on the owner’s tastes. The criterion for correct lighting is the rapid overgrowth of the upper half of rock structures. Keep in mind that with an excess of light and the absence of live plants, organics accumulate, and light will provoke the mass development of lower algae. The appearance of blue-green algae in the aquarium indicates an unfavorable lighting regime or salt composition of the water.
Large fish release quite a lot of organics and nitrogen and consume a large amount of oxygen. Therefore, filtration and aeration must be powerful and effective. A system with a capacity of at least 3-5 aquarium volumes per hour should be chosen. In this case, the required regime will be ensured even with intensive fish feeding and the maximum fish stocking density for this aquarium.
Excessively powerful current at the filter outlet can be damped by directing the jet toward the back glass of the aquarium, using a spray bar system downwards, or across the water surface. An ordinary internal pump with a porous sponge material nozzle works no worse than an external filter, but since the filter area is small, the filtering material has to be washed much more often.
Active aeration of water in the aquarium by means of continuously working air diffusers or filter ejectors must ensure maximum oxygen saturation of the water. The presence of nitrogen compounds in water with an alkaline active reaction leads to the formation of ammonia, which causes serious poisoning of fish. At low concentrations of nitrogen compounds, a filter with activated carbon can be used.
At least 20% of the water must be changed once a week. In aquariums with an alkaline water reaction where water is not changed regularly, organic residues are not cleaned, and water filtration is not carried out properly, poisoning of fish with ammonia formed as a result of organic decomposition is possible. The volume of replaced water depends on the stocking density and aquarium setup. In an aquarium without substrate and a biological filter, water needs to be changed more frequently and in larger amounts to prevent the accumulation of harmful substances.
Water discharge from the filter should promote maximum water aeration (arranged as a spray bar or equipped with a diffuser to form a water-air mixture). A heater with a large water heating volume should be installed near the nozzle from the filter pump so that the warm water current spreads throughout the aquarium. The recommended water temperature in the aquarium is within 25-27°C.
For lake Cichlidae, an acceptable pH level is about 7.8-8.5. Central American Cichlidae, similar in size and temperament, can be kept in general aquariums with lake representatives of the African ichthyofauna. They are ideally suited to the same water properties. Regarding the chemical composition of water, most American Cichlidae are unpretentious, despite the fact that in nature the fish inhabit different types of water, starting from practically distilled water, like inhabitants of Amazonia, and ending with brackish water, which is inhabited by Cichlidae of Nicaraguan lakes. An active water reaction pH of about 7, which corresponds to a neutral environment at medium hardness (8-12 degrees dGH), can be said to be suitable for all species without exception.
Nevertheless, Cichlidae of the Great Lakes of Central America (Managua, Nicaragua, etc.) feel better in slightly alkaline water with pH 7.5-8.5. Similar conditions are also beneficial for brackish-water Cichlidae, but an additional one and a half grams of salt per liter of aquarium water should be added. Inhabitants of the rivers of the western coast of equatorial Africa, as well as the Orinoco and Amazon basins, prefer slightly acidic water with pH 5.5-6.7.
Aquarium for African Savannah Cichlidae. Aquarium with Apistogramma.
Aquarium with Egg-laying Toothcarps. 
