With choosing aquarium soil attention should be paid to many points. Not every soil is suitable for your aquarium.
Many of the elements and particles that make up the stones or soil can be dangerous for aquarium fish. Let us dwell on the choice of aquarium soil and consider this issue in more detail.
Aquarium soil should meet the following requirements:
- It should not contain (even in a small volume!) Substances subject to rotting (humus, young peat, loam, sand smaller than 2 mm, perlite);
- The structure of the aquarium soil should be porous; for this, the soil is sized so that ventilation is provided, water freely penetrates the soil, the roots of the plants are saturated with oxygen and do not rot;
- The ability to accumulate and transfer nutrients to plant roots;
- It should not contain calcareous rocks (in large quantities) – the weakly acid reaction should be less than 7 (pH);
- To ensure the movement of water through and between the soil particles to prevent the appearance of aerobic (oxygen-free) zones, while at the same time there should not be an excess of oxygen in the soil;
- Should not damage the roots of plants, lump and clot.
It is desirable that the main aquarium soil meets several conditions. The most important condition is maintaining the physicochemical balance of water.
To do this, it is not recommended to put a lot of shells and corals in the aquarium, as they increase the water hardness and disrupt the alkaline balance. Also, you can not put crushed shells and sea sand on the bottom of the freshwater aquarium. If you do not adhere to this recommendation, the rate of water hardness will be too high, which will adversely affect the health of fish and plant growth.
The pH of the soil should be slightly acidic (pH is 7) or neutral.
The optimum size of soil particles for the inhabitants of the aquarium is from 3 to 8 mm, which is confirmed by the long-term practice of experienced aquarists. The soil of this fraction contributes to the formation of a favorable microclimate for microflora.
The root system of aquarium plants, melania (ground snails), most species of catfish, cichlids, as well as other representatives of ichthyofauna, whose existence is associated with the bottom of the aquarium.
For the formation of the aquarium bottom, you can use any soil satisfying the above conditions. However, colored ceramics, glass beads and other artificial materials are not used by experienced aquarists because they consider them to be not aesthetically attractive. Therefore, most often, as a soil for an aquarium with fresh water, pre-washed and sifted coarse-grained river sand, river pebbles, run-in chips from porcelain, bricks, ceramics, glass, as well as special plastic granules, expanded clay and coal are used.
When choosing the soil is recommended to stop on neutral solid rocks such as granite, basalt and quartz. It is important that the soil granules do not have sharp edges (fish can get hurt).
Bright soil usually increases the pH and hardness of water due to the release of bicarbonates and carbonates. The advantage of using river pebbles and sand is almost constant water hardness, gradually decreasing over time. There is an opinion that claydite accumulates organic matter in its pores, and if it doesn’t change the soil in the aquarium for a long time, then organic matter can be drastically released.
That is, expanded clay will become a dangerous accumulator of organic substances.
A beginner aquarist should be aware that the use of gravel and sand of rusty (red) or reddish color, as well as recruited from a pond or quarry contaminated with industrial wastes is harmful to plants and fish, as this soil contains iron oxides. Unsuitable for the aquarium bottom are crushed stone and stones having streaks with a metallic sheen, which indicates the presence of heavy metals in them. For the same reason, grains of gravel are carefully examined for the presence of minerals and rust in them.
Naturally, you can not use the soil pickled with agricultural poisons or waste oil. It is impossible to remove (wash off) them, therefore if a specific smell is felt, then it is desirable to refuse such soil.
Brick or concrete chips, as well as similar soils containing iron ions, are unsuitable for the aquarium bottom.
Some authors recommend using garden soil for planting in an aquarium, but experienced aquarists know that this is unacceptable. Such a soil will lead to the rapid growth of some types of algae, which will be very difficult to deal with (especially in volumetric aquariums).
Why when choosing a soil is recommended to stay on a chemically neutral and poor? Still, in nature, on such ground practically nothing grows. It turns out the answer is simple.
It is much easier, from the technical side, to know what useful substances in the soil are not enough and to add the necessary elements, than to find out what some rocks contain. In most cases, the water in tropical waters is very soft or soft.
Therefore, when choosing a soil, preference is given to mineral-neutral hard rocks (quartz, granite, basalt).
For aquariums with small fish that require soft water (slightly acidic or acidic environment), it is undesirable to use dolomite, limestone, marble chips and shell rock as soil. Since these rocks are rich in calcium carbonate, which dissolves in water increases its rigidity.
To determine the presence of a large amount of iron in marble can be on rust stains protruding on the rock surface. The formation of the bottom of the aquarium with the inclusion of limestone in the soil is permissible when breeding fish, which showed high water hardness.
The size of the soil particles significantly affects its functionality. Coarse-grained soil looks aesthetically attractive, creates a clear structure and optimal interior in a large aquarium. But at the same time, the aquarium is quickly polluted due to the remains of non-eaten food stuck between the pellets.
If the soil is too shallow, water circulation between the granules is impeded, and its biological filtration deteriorates. If plants have a well-developed root system, then river pebbles and gravel up to 8 mm in size are used, such a large soil is used in the cultivation of goldfish, cichlids, catfish, as well as other species of fish that dig the soil.
Peat crumb is used in aquariums with toothing toothfish. For plants with a delicate or underdeveloped root system, coarse sand is more suitable as a soil.
The color of the aquarium soil affects its decorative properties, but despite the fact that the color of the bottom is determined by the taste of its owner, it is recommended when choosing a particular soil color to take into account the color of the fish, the size and lighting of the aquarium. Soil in an aquarium fall asleep monophonic or combine two or more colors. Most often lay the soil for a long time (several years).
Replacement is usually carried out in the event that it is decided to completely reequip the aquarium. Usually, re-equipment and a complete change of soil is needed if signs of hydrosulphurous silting appear (the lower layers of soil turned black, the characteristic smell of rotten eggs appeared). When hydrosulphuric silting, the roots of plants first blacken, then die; algae grows poorly.
To prevent this unpleasant phenomenon, you should carefully remove debris and food residues from the surface of the soil. For lovers of aquatic plants is recommended to use coarse-grained river sand.
The excrement of fish and the remnants of other organics easily fall into the coarse-grained soil and feed the roots of plants, while large granules of sand (2-4 mm) easily pass water and oxygen necessary for the development of algae. The soil of river sand is quite porous, so the metabolic processes are not disturbed for a long time.
Such a soil is ideal not only for plants with a powerfully developed root system, but also for plants with delicate roots, since the optimal size of the granules with a careful transplant does not practically injure the root system.
Another important characteristic of the soil is porosity. Shallow river sand (particle size less than 2 mm) is unsuitable for the formation of the aquarium bottom.
Due to the rapid caking, the metabolic processes in it are sluggish, and then completely cease – the biological equilibrium is disturbed. Algae roots in rotting soil often rot, growth and development of plants is hampered.
Organic residues settle on the soil surface, therefore, on the one hand, with careful cleaning of the aquarium, the plants lack nutrients, and on the other hand, if the garbage is not cleaned in a timely manner, the water will be turbid. In the soil of fine-grained sand there is a violation of gas exchange, which leads to rotting and acidification of the roots of aquatic plants. In addition to problems with ventilation, the soil of small particles (thin sea or river sand) is not suitable for the formation of a multi-level landscape, because after some time the sand forms a completely flat field on the aquarium floor.
Also, fine sand is not suitable in combination with a bottom filter, the pores of the filter sponge become clogged and oxygen-free zones may occur in the aquarium. It should also be remembered that the river sand of rich yellow or red contains iron oxides, which are harmful to fish.
Gravel, sand and pebbles owe their origin to the same rock – granite. Granite is widely distributed in Russia, so the soil of it is most accessible to aquarists. The color of gravel, sand or pebbles can be different: from black and dark red to light gray and white.
It depends on the impurities of various minerals, but almost any type of granite rock is suitable for an aquarium. Impurities in water dissolve in small quantities, so they do not change the chemical composition of aquarium water.
One of the best soils is gravel 0, 2 – 0.5 mm. There are discrepancies regarding the use of fractions, however, small chemically neutral gravel is a universal option for the formation of the aquarium bottom.
After all, the more homogeneous and rolling the selected soil, the longer it serves without caking and without forming stagnant oxygen-free zones.
As a matter of fact, any purchased soil can be used as a soil – from small glass beads to branded soil (for example, polymer-painted sand) – the most important thing is that the soil meets all of the above requirements and satisfies the taste of the aquarium owner.
The main component for the formation of aquarium soil is fine gravel with a fraction of 0, 2 – 0, 5 cm. It fixes the roots of plants perfectly, is suitable for forming the top layer of soil, is also poured over peat chips and so on.
At the same time, fine gravel does not prevent nutrient organic substances from penetrating into the soil from the water, where they are absorbed by plant roots.
Among aquarists of great popularity of small pebbles (0, 4 – 0, 8 cm). The soil of this type of granite cracks much less than the soil of coarse sand and its silting occurs much slower.
However, the particles of this fraction can injure the root system of algae during transplantation, for this reason it is advisable to plant large plants with a well-developed root system into the soil from small pebbles. Coarse gravel or pebbles are used in large aquariums, and therefore much less frequently than shallow soil.
It should be noted that during the formation of the soil, each of its layers consists of heterogeneous fractions (the difference between particles is from 2 to 4 mm, depending on the type of soil). Experienced aquarists came to the conclusion that the soil with a fraction of 0, 2-0, 3 cm, which was previously considered the best option for aquarium plants, is subject to rapid caking and clogging. This soil gradually becomes completely anaerobic, and ultimately does not create any optimal conditions for normal growth and development of plants.
Therefore, it is recommended to use multi-layer primer.
To form the bottom of the aquarium with a pebble, a fraction is taken with a small difference in particle size, otherwise the pebbles will not mix, the substrate homogeneity will be broken, and as a result, the largest particles will gradually rise to the top, and the smaller will move down. Of course, when cleaning an aquarium, organic matter will fall into the lower, smaller layer of soil, and the aging process in the lower and upper layers will differ significantly in time. Shallow soil will quickly form an environment with a low redox potential and will effectively hold it during the first time of the aquarium.
Also, due to the blockage of a large fraction of the upper layer of pebbles with organic waste, the lower shallow soil more gently affects the redox potential of water.
As a rule, the middle fraction of the soil is used in large aquariums with algae, small – in medium and small aquariums with long stem plants, and large – ideal for the formation of soil in aquariums with some types of cichlids, as well as with large fish.