Let’s take the standard formula that for 1 centimeter of the length of a fish one liter of water is enough. It turns out that 10 gold fish with a length of 10 centimeters can be kept in a metropolitan aquarium. According to the formula, everything is correct. But by their nature, goldfish are very voracious, and in total with the characteristics of digestion, they quickly and extensively pollute the aquarium with waste.

Therefore, 10 goldfish in a stolitrovoy capacity. a large biological load on the aquarium, which leads to serious consequences. This means that “universal” formulas do not work in practice. To find out how many fish can be kept in one container, you need to take into account several factors.

### The main thing to push off

**The first thing you need to pay attention to is the physicochemical parameters of water: acidity, amount of nitrogen compounds, O2 saturation and temperature. An important limiting factor is the oxygen content in water. Plants and equipment. additional sources of gas. allow you to increase the density of landing fish. It is easy to determine if the water is sufficiently saturated with oxygen: if, with high-quality aeration, the fish swim at the very surface, they are convulsively swallowing the air. overpopulation in the aquarium.**

The next parameter concerns the fish themselves: their number, size, mass, age, food activity and growth rate. The larger the individual, the more waste from it. They decompose with remnants of food, emit poisonous ammonia. In overpopulated capacity, it does not have time to be processed, and its excess literally poisons the aquarium.

**It is also important to consider:**

1. The quality and quantity of soil.

2. The presence of live plants in the aquarium.

3. Availability of filtering equipment and its power.

4. The frequency of water changes, cleaning the soil, the aquarium itself, etc.

5. In what quantities and how often do the fish eat.

**There are other factors that influence the amount of fish that can be kept in one aquarium, but the ones listed above can safely be considered fundamental.**

### Methods for optimal filling of the aquarium

**There are several ways to determine the optimal amount of fish. The first one says that 3.5 centimeters of fish should account for 5 liters of water, where 3.5 is the total length of all individuals. This method has several disadvantages:**

1. It is necessary to clearly know the size to which each fish will grow.

2. It is necessary to take into account the physical shape of pets. Large individuals produce more waste than thin ones, which means they need more water.

3. Only real volume of water is taken into account in its pure form. without soil, stones, algae and other accessories, which on average occupy about 15% of the total.

**The following method is based on determining the surface area of water. To learn it you need to multiply the width of the aquarium by the length. The larger the area, the more intense the oxygen exchange and the more fish can be settled in one aquarium. For large pets it is possible to consider the optimum ratio of 3 cm of the body to 150 cm² of the surface, for more slim and elongated ones. to 90 cm².**

In any method errors are possible. it is better to err and leave a margin in the calculations.

**Some more useful rules:**

1. Use the rule “1 centimeter per 1 liter of water” only for small, thin, calm and unpretentious pets.

2. The greater the length and height of the body of the fish, the more water it needs. For example, a 20-centimeter discus requires at least 40 liters of water.

**3. Small containers are good for keeping small fish.**

4. For aggressive creatures, choose a larger aquarium.

5. Sometimes a good filtration can save even a densely populated aquarium.

6. Choose fish, based on what layer of water they prefer to swim. So the aquarium will be settled, and pets will live in peace. To find out who is who is simple enough: the mouth is turned upwards. the fish likes to swim in the upper layer, it is directed along the middle line. on average, it looks down. the bottom rock.

### Each type of fish. its own amount of water

**The ideal option for settling an aquarium is to focus on the characteristics of the type of pets:**

1. Tiny fish up to 4 centimeters. neon, cardinal, guppy, rasbora. you can settle in aquariums from 10 liters with a density of landing 1 liter of water per fish.

**2. Small pets up to 6 centimeters. petilia, crescent, hasemania, rhodostomus, minor, guppy, barbus. can be kept in 20-liter containers with a density of 1.5 liters of water per pet.**

3. Small peaceful creatures up to 10 centimeters, such as an apistogram, a swordtail or mollies, are best kept in aquariums of 150 liters or more. Density. 3-10 liters per fish.

4. Peaceful fish up to 20 centimeters. an angelfish, goldfish, gourami, danios. are settled in large containers of 200 liters. But this is not true. it all depends on the temperament of the fish, its habits.

5. A pair of small cichlids up to 10 centimeters need at least 40 liters.

**6. Large creatures up to 30 centimeters in size. akara, astronotus, tsikhlazoma. settle in pairs or ten in a 250-liter or 500-liter aquariums, respectively.**

7. For discus, you need an aquarium with a volume of 200 liters and 50 liters per person.

8. Large fish. arovan, snakehead, catfish. need a large area. They are settled in aquariums at least 1.5 meters in length. At 500 liters should fall no more than 1-2 fish.

9. As for the labyrinth, then one Betta Fish will be enough 2 liters, a pair of gourami. 20 liters.

**To solve the problem of how many fish can be kept in one aquarium is possible, taking into account the peculiarities of the aquatic environment and the parameters of the pets themselves. The formulas are not just possible, but you need to listen, but to rely on them as the truth. in any case.**