What is necessary for the normal functioning of the underwater world.
Freshwater aquarium equipment. How to choose it and what is it needed for? Having decided on the aquarium, its design, and who is planned to be housed there: aquarium fishes and other hydrobionts, it is necessary to determine the habitat and equipment that will monitor and maintain the microclimate for the well-being of your pets. Equipment located inside the aquarium (internal filter, heater, etc.) should be of neutral colors – black, green – and placed so that it does not catch the eye. If necessary, it is masked with decorations. Therefore, when purchasing equipment for the aquarium, adhere to the basic rules that will subsequently help create ideal conditions for the life activity of the aquarium and its inhabitants.
A very important kind of equipment for the aquarium is the substrate in which plant growth is planned, as well as stones that create a special decorative effect. As a rule, aquarium decoration begins with the choice of substrate, taking into account its characteristics such as color, size, shape, and mineral composition. Substrates of natural origin are typical for amateur aquariums: river gravel, sand, granite, marble chips, etc. Such substrates are widespread, and therefore cheap and accessible to a wide range of home pond enthusiasts. They can be harvested independently or purchased in pet stores and markets already washed and packaged. The thickness of the aquarium bottom coating should be at least 3-5 cm. This is quite enough for the excellent growth of live plants.
Color, shape, and height of plants, texture of stones and driftwood, their placement – all these elements of aquarium decoration in skillful hands become effective means of creating beautiful home ponds. If the primary focus is on keeping specific fish or plants, the substrate must be chosen based on their maintenance requirements. From the standpoint of aquascaping, the defining factor of the substrate is its color. For example, the color of river gravel varies from light gray to dark brown and gray. Granite, depending on its mineral components, can be black-and-white, black-red-gray, red. Marble chips also differ in color variability.
Substrates of natural origin are most appropriate in aquariums where design styles recreating natural water landscapes are used: with live plants, natural driftwood, stones. The only exceptions are marble and coral chips, which excessively saturate water with calcium salts, causing most live plants to feel uncomfortable. Against the background of natural substrates, artificial plants mimicking real prototypes, or various subdued (grayish, brownish) ceramic or plastic structures look good.
Additional difficulties may arise when searching for a substrate of the desired size and shape. Too fine a substrate is poorly ventilated, while excessively coarse substrates form cavities where uneaten food particles accumulate and rot. For the root system of live plants, as well as for fish that like to burrow into the substrate, a substrate with rounded edges is needed.
The mineral composition of many natural substrates makes them unsuitable for aquarium keeping due to the presence of certain chemical compounds which, dissolving in water, can cause significant harm to the health of the home pond’s inhabitants. Such problems can be avoided by using artificial aquarium substrate produced by well-known firms specializing in the pet industry. Moreover, there is currently a wide selection of multicolored foreign-produced artificial substrates available from a number of companies.
Artificial substrate has a rounded shape and is inert to water, so it can be used with all types of plants and fish. Another useful property of artificial substrate is its relatively low specific gravity, thanks to which plants take root well in it. But the main advantage of artificial substrate over natural one is the variety of colors.
To achieve the desired effect, colored substrates can be mixed in arbitrary proportions, obtaining original resulting colors. For example, mixtures of blue and green, red and yellow, blue and white substrates look good. They are combined with artificial plants of both natural and avant-garde color ranges (pearly, black, pink). The use of bright multicolored substrates gives the pond a unique flavor. However, it is important to properly select other interior items of the aquarium so that it turns out harmonious. Various contrastingly colored castles, grottoes, and caves are appropriate here.
For aquariums with bright substrates, goldfish, swordtails, guppies are best suited. When choosing fish, the main thing is that they are not pale and have at least one bright color in their coloration. Among the wide palette of artificial substrates, one can single out a more or less universal one – black. Against its background, plants and fish of any shapes and colors look equally attractive.
Substrate heating. Good results can be achieved through the use of heating cables. The effect of their application consists not only, and perhaps not so much, in heating, but in creating water flows in the substrate (ascending warm currents above the cable and descending cold currents between cables), which prevents the substrate from souring. The cable is laid along the bottom of the aquarium and covered with substrate. Cables are available both powered by 220 V and powered by a step-down transformer. The second option is safer in case of cable damage, but also significantly more expensive.
Water in the aquarium should be soft – from 5 to 8°. In principle, in most cases, a temperature of 24-26°C will be optimal for an aquarium with plants and fish. Filtration and aeration should preferably be round-the-clock. Water should be changed 1-2 times a month (up to 30% of the total volume).
Aquarium design involves both the decoration of the tank walls and the filling of the aquarium with various decorative elements, one of the main functions of which is not just to attract the attention of others, but, first of all, to create excellent conditions for aquarium fish to spawn and reproduce. The second step is the selection of decor elements: stones, driftwood, ceramics, plastic products, and much more – and each of them can also have its own impact on water properties, for example, driftwood acidifies water and releases certain amounts of humic acids. At the same time, decor elements should fit into the general style of aquarium decoration, being part of the aquarium design. In some cases, design elements can be skeletons of living corals, mollusk shells, live plants, willow roots, and various non-traditional items.
Plants, as aquarium equipment, can be either artificial or live. The choice depends only on your preferences, but it should be remembered that live plants not only look more aesthetic, but are also able to process the waste products of the fish themselves. The only downside of live plants is that they are quite demanding in terms of lighting, and besides, they can become an excellent snack for aquarium inhabitants. And for such representatives of the underwater kingdom as Astronotus or goldfish, live plants are generally contraindicated!
Since we are going to densely plant our aquarium with vegetation, we will have to use a nutrient substrate. That is, the first layer of substrate that the plant roots reach must be rich in nutrients. Ready-made solutions from leading manufacturing companies can be used as nutrient substrate: gravel enriched with clay, laterites. Before planting, be sure to disinfect them in a pale pink solution of potassium permanganate for 10-15 minutes.
Light is one of the main factors in growing aquatic plants. When buying an aquarium, you should pay attention to the light source. In most aquariums, both imported and domestic, the standard light source is sufficient for keeping fish, but insufficient for growing plants. Therefore, you should pay attention to the possibility of installing additional lamps and reflectors in the lid. In most cases, a reflector increases lighting efficiency by one and a half times or more. The light should be top, diffused, coming from the front.
Usually, fluorescent lamps are used as a light source in aquariums. It is better to use specialized lamps as they have improved spectral characteristics. Currently, apart from conventional T-8 fluorescent lamps, T-5 fluorescent lamps have appeared, which have higher power and smaller dimensions. Plants need a stable daylight hours, so you will also need a timer to automatically turn the lighting on and off. For most tropical plants in their natural habitat, daylight lasts up to 12 hours. Excessive daylight hours provoke algal growth.
CO2 (carbon dioxide). In a planted aquarium, CO2 supply solves many problems at once – from plant growth to algae control. For most plants, 
increasing the carbon dioxide content in the water leads to a significant increase in growth. The optimal concentration can be considered 5-15 mg/l. To supply CO2 to the aquarium, you can buy branded setups, assemble them from more affordable components, or in small aquariums, use tablets produced by some companies, or even the fermentation process.
Naturally, the list of equipment for the aquarium must include a filter pump, which will perform two main functions: clean the water from dirt and saturate it with oxygen. The choice of filters today is truly huge. But you should not spend money on professional canister filters. If the volume of your aquarium does not exceed 60 l, the simplest filter will do. Round-the-clock filtration is necessary.
The concept of aquarium equipment also includes a heater with a thermostat. Modern heaters with a built-in thermostat are very convenient to use because the heater turns off automatically as soon as the water reaches the desired temperature. Although a regular aquarium thermometer will not hurt either. In principle, in most cases, a temperature of 24-26°C will be optimal for an aquarium with plants and fish. But sometimes you have to keep the aquarium at a temperature of 28-30°C (if discus, angelfish, etc., live there).
At elevated temperatures, plants can also grow. The temperature limits indicated in reference books are not the maximum possible limits for a plant; these are the temperature limits found in the natural biotopes where it grows under natural conditions. But in this case, all processes proceed much faster, so the plant needs more light, more CO2, more fertilization. Moreover, with a lack of any of these factors, plants wither and die. At high temperatures, the solubility of gases in water drops, while the plant’s need for CO2, on the contrary, increases, so carbon dioxide supply will most likely be required. And fertilizers will have to be applied regularly.
Decorations in the aquarium. Design and decorations.
Design of a traditional freshwater aquarium. 
