Aeration of water in the aquarium is one of the vital conditions for the normal existence of living organisms in an aquarium, especially with a significant number of them. Aeration contributes to a favorable gas exchange regime in the aquarium, saturation of water with the necessary amount of oxygen.
The concentration of oxygen dissolved in the water is directly dependent on the population of the aquarium, its depth, surface area, light conditions, water temperature and some other factors. A huge role in maintaining the normal oxygen regime in an aquarium is played by aquatic plants. In large aquariums that are well planted with plants and contain a relatively small number of fish, self-oxygenation is possible, since it is produced in sufficient quantities by photosynthesis. At first glance, its additional supply by aeration, i.e. blowing air through the water is superfluous. However, in practice, as a rule, there is a lack of oxygen.
Aeration in an aquarium is usually carried out by blowing atmospheric air through the water column, during which it, divided into the smallest bubbles, comes into contact with water and enriches it with oxygen in it. The more active the air will be sprayed on the many tiny bubbles, the greater will be the surface of its contact with water and the return of oxygen to it. There are other ways of aeration.
Aeration of water in aquariums is carried out mainly in two ways:
1. water pumps, pumps, filters having a diffuser. Water pumps are usually part of the internal filters. They drive water through a sponge and those that have a diffuser suck air from a special air tube. The latter in the diffuser is mixed with water and in the stream, in the form of tiny bubbles, is released into the aquarium.
2. And as mentioned earlier – air-water pumps that supply air to the aquarium through air tubes through a spray bottle. Air-driven air pumps are specifically designed to supply air to the aquarium water column. A nebulizer is connected to them through an air hose, which serves to spray air into the smallest bubbles. Water pumps vary in power, capacity and maximum pumping depth.
An additional purpose of aeration in an aquarium is the mixing of water in a domestic pond. A heater that heats the water in an aquarium is usually in the corner. The sprayer should be placed near the heater so that different temperature zones in the aquarium are not created. Streams of warm water quickly rise to the surface. Also, the warm water for the most part is located near the heater. And the movement of bubbles evenly mix the water, thereby not leaving the lower layers of water in the aquarium not warmed up.
In addition, the water in the aquarium is enriched with oxygen through the surface, in contact with air. It turns out that in the upper layers of oxygen more than in the lower. Aeration quickly helps to mix the upper with the lower layers of water. The bubbles pull the bottom layer of water to the surface, helping it, saturate with oxygen.
Place the water pump necessary for aeration in the aquarium, be sure to above the water level or install a check valve on the air duct near the water pump so that the water through the hose does not leak out of the aquarium when it is turned off.
The main disadvantage of membrane water pumps is significant vibration and annoying noise accompanying the operation of the pump. To what tricks aquarists do not resort, struggling with the noise of water pumps: they put all kinds of gaskets, and wrap them in foam rubber, but still the noise of cheap models comes to 45-50 decibels. Foreign manufacturers are more humane towards consumers. Shock absorbers where necessary, as a rule, are already installed. True, the noise is not completely extinguished, but its intensity is significantly reduced.
The noise level of the most "quiet" models, with a capacity of 100-150 l / h, is 25-30 decibels. Low-frequency noise annoying some people is a minor flaw that can be corrected by placing a water pump in a sound-absorbing shell, such as foam plastic. You can install a water pump not in the cabinet under the aquarium, but for example, take it to a loggia in a warm time or move it to another room, but rather to a pantry, or put it on the mezzanine. This will require a long hose from the water pump to the aquarium to the sprayer. You can hold it under the baseboard, and the problem of noise will be solved. In this case, you need a fairly powerful water pump.
It is possible to reduce the noise of a water pump by placing a foam rubber damper under it. To reduce the noise of the water pump, it can also be connected via a step-down transformer, but at the same time its performance is reduced. The water pump must be periodically disassembled and the valve cleaned, since dirt is one of the reasons for reduced performance and increased noise.
Factors affecting the oxygen content in water.
Water temperature affects the oxygen content in water: the warmer the water, the less oxygen it contains, and vice versa. In addition, the increased temperature accelerates the metabolic processes in fish, with the result that their oxygen demand rises precisely at a time when its content in water decreases. This problem can be overcome by more intensive aeration of water in the aquarium.
Aquarium plants are often appreciated for their ability to produce oxygen. However, it should be remembered that at night they themselves consume oxygen and produce carbon dioxide. Thus, although plants can really help to meet the oxygen requirements of fish during the daytime, at night, all living things in an aquarium compete for oxygen, the content of which at this time of day is decreasing. Therefore, in aquariums, densely planted with plants, at night there may be a lack of oxygen.
Snails and other living things.
A large population of snails can have a significant effect on the oxygen content of an aquarium. Bacteria can do the same. Oxygen consumption by aerobic bacteria involved in the nitrogen cycle is permissible because, instead, they bring significant benefits. However, if there is an excessive amount of organic waste in the aquarium, for example, due to regular overfeeding of the fish, the bacteria population will grow and absorb more oxygen than when the fish are fed rationally. Snails, of course, also increase the content of organic waste.
Aeration of water in the aquarium should be carried out around the clock, ensuring a stable gas exchange regime. Little that gives a periodic, short-term so-called pumping air into the aquarium – it can even harm fish and plants, causing sharp changes in the amount of oxygen in the aquarium and disrupting their livelihoods.
The minimum required pump capacity depends on the volume of the aerated aquarium or the total volume of several aquariums and is determined on the basis of: 0.5-0.7 liters of air per hour per 1 liter of water. It is better to buy a water pump, especially if it is single-channel, with a double or even triple reserve of performance, at least 1.5-2 liters of oxygen per hour for every liter of aquarium water, since it is possible that in the future you will use several sprayers on each channel, and then the low-power pump will be powerless.
The maximum possible depth of immersion of the sprayer depends on the pressure created by the pump vodushny and here the height of the aquarium serviced by the aerator, as well as the material of the sprayer, is a guide. In high aquariums, the lower layers of water are poorly saturated with oxygen, which leads to the need for a mandatory aeration of the water with a pump. The higher the aquarium, the more powerful the water pump is required to create more pressure. It is better to purchase a water pump with a pressure reserve, since over time, the resistance of the sprayer increases due to clogging of the pores. In order to ensure a uniform supply of oxygen during the day, it is necessary to resort to automatic adjustment using a time relay, making sure to coordinate its operation with switching off the lighting. In this case we are talking about the night aeration of water in the aquarium. In the daytime, live plants work effectively.
To intensify the saturation of water with oxygen requires the maximum number of air bubbles of the minimum size. The effectiveness of aeration depends on the quality of the sprayer. It should be dense enough to give small bubbles. The size of the bubbles significantly affects the enrichment of water with oxygen. The smaller the bubbles, the better the oxygen goes into the water.
Tests have shown that with aeration with small bubbles with a pore diameter of about 0.1 mm, oxygen enrichment of about 10 g per cubic meter of air is achieved at an immersion depth of 1 m. While aeration with large bubbles is 2 mm in size. reduces this value by half.
Most sprayers, among which emit ceramic, carborundum, wood, plastic and others, provide gas bubbles with a diameter of 2.0-2.5 mm. Air bubbles that rise constantly take along the boundary water. As a result, there is an upward flow of water. There is a very small difference in velocity between water and air bubbles. The bubble moves in a very uniform flow and the more pronounced the turbulence is, the better the surface layer will be removed on the bubble that is saturated with oxygen. Water depleted in oxygen is rapidly supplied to the surface of the bubble and enriched with oxygen.
The use of porous stone is ensured primarily by water turbulence. Large bubbles quickly rising up easily contaminate the upper glass and interfere with the aquarium lighting. The use of air bubbles formed by a spray from a water pump can serve as an additional element for decorating an aquarium, and for saturating water with oxygen. When the pores of the sprayer are clogged, it can be restored by first removing the plastic tip by calcining on a fire or by immersion in acid.
It is impossible to use conventional sprays when ozonating water. Sprayers should be made of plastic, and air ducts made of polyethylene. In no case can not use metal parts, because they will react with ozone.
Experience has shown that the best bubbles are obtained from wooden sprays, which are made of lime and give the smallest bubbles. Lime sprays do not require a very large pressure from the water pump and create a uniform current of bubbles during the entire service life, which, unfortunately, usually does not exceed 2 months, the pores quickly become clogged.
The most commonly used for aeration of water in an aquarium are short cylindrical nozzles made of brownish-colored abrasive materials that give excessively large bubbles. Slightly better sprays made of white grinding stone. But those and others are suitable for equipping the absolute majority of even the most low-power pumps. Ceramsite sprays are distinguished by maximum efficiency. Ceramic sprayers give smaller bubbles than dark-colored abrasives and white ones made of a grinding stone, but they require water pumps that develop a pressure of at least 1000-1500 mm of water column. However, they have one drawback in common with abrasive sprays: a narrow column of bubbles creates not very efficient circulation of water in a spacious aquarium.
In order to bring the interior of the aquarium closer to the natural one, the sprayer can be decorated with the upper layer of soil, but only with a large, log, plants or stone ridge. The sprayer must be placed on a stone or placed at a short distance from the ground so that air bubbles do not lift particles of dirt. They are easy to disguise, putting on the ground and pressing something heavy. Without additional fixation of the hose or the sprayer itself, with a sufficiently intense air supply, it rises to the surface.
Sprayers that receive air through the same line can pass through different amounts of air due to different lengths of pipelines, hose bends, and debris in the nozzles themselves. Therefore, on the line of each spray you need to install a tap-valve to regulate the air supply.
Nozzles for air ducts in the vast majority of water pumps are designed for hoses with an internal diameter of 5 mm. With most pumps, they have a flat cylindrical shape, and putting the hose on requires some physical effort. To facilitate the procedure, a chamfer is usually made at the outer end of the nozzle. It is much more convenient to have pipes with a slightly tapered profile, it is easier to put a hose on them, and they hold as tightly, especially if they have embossed walls. So when buying do not ignore this seemingly insignificant detail.
Care should be taken when purchasing the hoses themselves, which are also necessary for aeration in the aquarium. If the kit to the water pump offers an opaque rigid hose made of thin white PVC, it is better to abandon this “service” and search for the hose yourself. The tubes should be made of synthetic rubber, in extreme cases, of bright red rubber. Rubber medical hoses are of little use. Tubes of black color contain toxic impurities, yellow-red contain harmful disinfectants. They should be elastic, soft to the touch, camouflage color or transparent, preferably with a certain margin in length. One measure of the quality of the hose is the diameter of the bend without the formation of a crease. Naturally, the smaller the bend diameter, the better.
Twins and tees can be plastic or metal. The second ones are more expensive, but they break less often, and chrome plating ensures a decent appearance even after prolonged use. It is better to purchase splitters with faucets-regulators. This will allow not only to equip the water pump with several sprayers, but also to provide independent control of air intake to each of them.
It is advisable to use check valves on the hoses from the water pump. There are many models of such devices, here you can choose the taste and color yourself. Best of all proven check valves from the company Tetra. Convenient to install, original in design, the nipple membrane system inside the valve is reliable and practical.
If the valve is installed closer to the water pump, when aeration is turned off, water can fill the hose to its full length to the place where it is installed. If, what is correct, the valve is installed on the hose, just above the water level, water does not get into the hose and when the water pump is turned on, it will have to push the water out of the hose in a small area, from the valve to the sprayer.
The valve is a very useful and necessary accessory for the water pump. After all, the disconnection of total electricity is a common fact, and we can at this time be at work, at school, in the country, on vacation, etc. I would not want to contemplate leaked water from the aquarium to the floor, and even worse to the neighbors.