A water pump is a device that is capable of creating air pressure that is sufficient to purge the entire volume of the aquarium with air. For these purposes, you can also use internal filter pumps (how we used them for this purpose in the article “Installation options for the internal filter”). But today we will analyze exactly the use of water pumps.
The purpose of water pumps is one – the organization of aeration in an aquarium. During which, above all, water is saturated with oxygen. Rising to the surface of the bubbles lead to the mixing of water layers, going to the surface destroys the bacterial film, and can also serve as a "transport" of water in the airlift filter.
The main division of vodoshnyh pumps into types occurs according to the principle of the mechanism that creates pressure in the system and which are:
Membrane Water Pumps
The most commonly used are membrane water pumps. This is due to their simplicity and simplicity of design. The main part of these devices is the membrane. This is a cuff made of rubber or any other elastic material, which is internally connected to the air outlet of the device. In order for air to be supplied in one direction only, two check valves are used. For the membrane to start creating pressure, it needs to be given a reciprocating motion. This role is performed by an electromagnet, which magnetizes with the frequency of the alternating voltage applied to it and is connected to the membrane with a lever. All structural elements are mounted in a single compact case.
The advantages of such structures are:
Ultimate simplicity mechanism. The absence of a large number of moving parts makes the design very reliable. In such vodshnogo pumps simply nothing to break.
Lack of serviceable parts. The only serviced part is the air filter, which are equipped with some models and in the case of pollution is replaced by a new one.
Sufficient performance for most users, which is combined with compact size. There are water pumps with a capacity of 60 0 l / h available for sale. At the same time, overall dimensions allow not to select a special place for their placement, but to place them in the pedestals under the aquarium or directly next to it.
Low power consumption. water pump with a capacity of 9 0 l / h has an energy consumption of about 3 watts.
Low cost of membrane type water pumps as compared with piston models.
But the disadvantages of these devices are also significant:
The main drawback is the noise. Because of the movable lever that deforms the membrane, noises and vibrations occur in structures of this type. Designers go to all sorts of tricks to reduce them: the soft shock-absorbing legs, the horizontal and vertical position of the membrane, different shapes and sizes of cases are used. However, these measures can only reduce the negative manifestations, as they are a consequence of the design features. We can say that the best in noise are models in which two balanced membranes are applied.
The elastic membrane undergoes constant alternating loads, with the result that over time it begins to lose elasticity and crack. Therefore, after a certain period of use of a water pump, its performance drops, and, after the membrane is destroyed, the device stops working. True, this disadvantage is more than compensated for the low cost of the device itself.
Piston water pumps.
Piston-type air pumps are structurally more complex. They are equipped with an electric motor that rotates the flywheel, which drives the piston located in the cylinder. The piston reciprocates and, with the aid of a check valve system, supplies air to the output line. All elements are structurally made in one case. Let’s consider the advantages and disadvantages of such structures.
The advantages include:
High performance. Devices of this type have much higher power and performance. Able to blow large volumes of water at a substantial depth. Often used to maintain multiple aquariums. It can easily pull out the maintenance of small ponds, as there are models with a capacity of about 17,000 liters / hour. They can be used for servicing several aquariums using one device, which is more profitable than using several membrane-type water pumps. The noise level that can be created by 5-6 membrane water pumps installed in the same room is quite high.
Piston water pumps have much lower noise levels than their membrane counterparts. The design here has a significant impact. If the manufacturer does not save on the size of the piston and the quality of the seals, the required performance is achieved at a lower speed of rotation of the electric motor, which has a positive effect on the noiselessness of a particular model
Of the minuses can be identified:
The price of piston water pumps significantly exceeds the cost of the membrane.
Larger dimensions and weight require more careful selection of the device placement location.
A more complex design than that of a membrane type water pump can potentially affect the reliability of the product. Although much depends on the design solutions and materials used by the manufacturer.
Which to choose?
The choice of a particular type of water pump depends on the requirements that you present to the product. For home use in most cases, a device of membrane type is sufficient. True, in this case you will have to take care of the installation place where the noise background will not prevent you from enjoying the beauty of the aquarium.
Also, when choosing a particular model, pay attention to the performance of the device. The main problem here is that the manufacturer often indicates maximum values measured during installation of the device without any spray equipment and supply systems. Connecting a simple hose to the water pump will reduce air flow. As a result, the amount of air pumped through the water, expressed in liters / hour, will be the smaller, the higher:
feed system resistance.
height of the water column in the aquarium.
The number of serviced tanks.
Feed System Resistance consists of the resistances of the hose, valves, adapters, check valves and other equipment mounted between the pump and the sprayer. To achieve maximum performance, you must use the shortest hose of the largest diameter without any additional devices. It is clear that in most cases this is not achievable. The hose length is dictated by the ease of placement of the device, its diameter is limited by the diameter of the outlet fitting. And without cranes and adapters, in the case of work on several containers, is also not enough. Another thing is that when connecting and mounting an aeration system, it is necessary to use their minimum number. This will have a very positive impact on system performance and will save you from buying a more powerful and expensive model.
Spray resistance – This is another powerful factor leading to a decrease in the productivity of the water pump. For more intensive saturation of water with oxygen, a nebulizer is required, which forms small air bubbles. The smaller they are, the more effective this process is. The problem is that as the size of the bubbles decreases, so does the resistance of the sprayer.
Water column height in the aquarium also affects the efficiency of the aeration process. The deeper the sprayer is lowered under water, the more intense the process, however, increasing the depth drastically reduces the air supply.
The number of serviced tanks significantly reduces performance, requires the installation of adjustment valves, which also add resistance in order to adjust the flow to each individual aquarium. Multichannel water pumps are available. They have several air chambers that operate independently, and each can serve a separate aquarium.
When a certain amount of three resistances is reached, the air supply may stop altogether and the device will run idle. The exit consists in reducing the length of the air supply line, switching to a sprayer of a coarser structure, or reducing the depth of immersion of the sprayer. It is also possible to choose a more powerful model of a water pump. It is worth mentioning that it is better to purchase the device with a margin of power. This will help you in the future to avoid replacing an already purchased product when you want to expand your aquarium farm or switch to large volumes.
How to install?
It is better to install the water pump in places that are closed from view so that it does not spoil the appearance of the aquarium. Also it is worth remembering the noise created by the device. Placing the product as far as possible from the place of rest will significantly reduce the load on your hearing. Not a bad solution would be to install the device itself in a non-residential area (for example, in the corridor), in this case, you must pass the connecting hose through the hole in the wall to the aquarium. You should not install the device outside the window, since large temperature fluctuations negatively affect the state of the membrane and thereby reduce the service life of the device. The most silent can be called models produced by firms Fluval and Schego.
It is also worth mentioning that almost all manufacturers of water pumps in the documentation for their devices prohibit their installation below the water level. This is due to the fact that if the water pump stops, the water can flow by gravity through the air hose, overflowing the aquarium, which will lead to flooding. If it is not possible to install the device above the level of the aquarium, it is necessary to install a non-return valve in the open air supply. This miniature fixture will save you from many problems. The principle of its operation lies in the fact that the air can freely pass towards the aquarium, but in the opposite direction the valve is always closed.
In addition, I recommend you to experiment with the method of installing a water pump. If the model is noisy when installed on the legs, try to hang it. Choose a place where it stands, so that there is no resonance.
Sprays are used to create a stream of air consisting of small bubbles. The smaller the size of each individual bubble, the more surfaces of contact of air with water, and therefore more aeration occurs. Sprays are made of natural stone, ceramics, wood. Differ in shapes, sizes, color. They can be a small cylinder or a complex system of tubes that must be attached to the glass by suction cups. It is worth noting that they form the smallest bubbles of wood sprayers, however, due to their dense structure, they require the most powerful water pump. Small holes in the nozzles become clogged with time, in which case they must be replaced.