In nature, lakes with crystal clear water usually have a large area, while small ones often turn into swamps. Therefore, in order for artificial ponds to be pleasing to the eye, they need care. The transparency of water in an artificial reservoir is ensured not only by performing regular procedures for its mechanical cleaning, but also, first of all, by a competent design for the arrangement of the pond itself, as well as by the operation of a water filtration and aeration system. The sum of the mentioned factors should provide establishing a biological balance in a reservoir lower and higher flora and fauna, the existence of which is evidenced by clean water without an unpleasant odor.
When arranging an artificial pond, its main parameters play a key role - location, volume and purpose. Choosing place, take into account that the reservoir should be illuminated by the sun for 4-6 hours during the day, and at summer noon, shading of at least 40% of the water surface is necessary. At the same time, the pond is not located directly under the trees: falling leaves or needles have a bad effect on its biobalance.
The water in any artificial pond must be continuously enriched with oxygen and regularly pumped through a filtration system, the type of which depends on the purpose of the reservoir.
Decorative pond with an area of 8-12 m2 with a maximum depth of about 60-80 cm, it is aimed exclusively at growing ornamental plants. In this case, the problem of enriching water with oxygen is often solved using an external compressor (aerator), which pumps air into the water column. The compressor, along with a cleaning filter and a pump, the parameters of which are selected based on the size of the reservoir, are installed in a secluded place on the shore of the pond. Filtration is ensured by taking water from a pit in the deepest part of the reservoir and returning it to the pond on the side opposite from the point of intake.
Pond for fish must have a deep-water zone (80 cm or more) for the wintering of living organisms, the area of which should be a significant part of the pond. There, the water will not warm up much during the summer heat and freeze in winter. The area of a fish pond usually exceeds the minimum size of a decorative pond and can reach 50 m2. The number of individuals is selected based on the fact that per 1 m2 of pond area there should be no more than 0.25 m of the total body length of the fish. To purify and saturate the water with oxygen, you will have to install an aerator complete with a multi-stage filter.
Bathing pond, the area of which exceeds 70 m2, and the depth can reach 1.5 m, must be equipped not only with an automatic filtration and aeration system, but also with a special zone for natural purification and biological regeneration of water. The swimming and regeneration zones of the pond can be combined or separated into different areas. When organized jointly, the regeneration zone should be separated from the bathing area. It is necessary to build dividing walls 20-30 cm below the water level. The role of a dividing wall can also be played by a tightly stretched fine-mesh mesh, which needs to be changed every few years. The volume of the bathing and regeneration zones is usually 1:1 or 1:2.
In any artificial pond, regardless of its size and purpose, protozoa and higher plants, as well as insects and microorganisms, coexist. Most lower plants and microorganisms grow on their own, but the owner of the reservoir must take care of breeding higher ornamental plants and fish.
To maintain a healthy biological balance in the pond, it is necessary to grow oxygenating algae floating in the water column- swampweed, pondweed, hornwort, turcha, urut and elodea. These plants process organic matter in the water into green mass and saturate the reservoir with oxygen, thereby maintaining the normal functioning of other organisms. When oxygenators grow too large, the excess is removed manually.
In addition, the pond should grow free floating plants(watercolor, hornwort, telores) and deep-water perennials with floating leaves(marsh flower, water lily, water lily). They are not only decorative, but also useful, as they shade the water during hot weather. In reservoirs with fish, ⅓ of the water surface should be covered with surface greenery, but it should not be allowed to grow over more than ½ of the area.
The pond must be periodically cleared of debris floating on the surface and excess aquatic plants. If the water becomes cloudy, measures should be taken to establish biobalance. Leaves and other organic debris that fall on the surface of the water quickly become wet, settle to the bottom and after some time begin to decompose. To remove leaves and debris that fall into the water, you can use skimmers. These floating devices are a basket into which dirt from the water surface is automatically collected.
In autumn, during leaf fall, you can even stretch a special mesh. As a last resort, use a net, but then you will have to collect leaves every day. In the spring, the reservoir is pumped out (leaving the liquid in the regeneration zone of the swimming pond and in the deep-water section of the fish pond) and clean the surface with a suction pump. In addition, in the fall, overgrown aquatic plants should be pruned and, if necessary, replanted.
Special filter systems that ensure the purity of water in the pond must contain mechanical cleaning elements- containers with porous filter material, which allows you to clarify the water by removing debris and dirt particles. In addition, the filter may include components of light and chemical-biological purification. They are used to disinfect and purify water from toxins using ultraviolet light and filter substances such as carbon or resin. To normalize the microflora of water, a separate compartment of a multi-stage filter may contain capsules with beneficial microorganisms. The main goal of such multi-stage filtration is not so much mechanical cleaning as the normalization of the biological balance of the reservoir, when the development of unnecessary algae and harmful bacteria in the pond is naturally suppressed. Filter elements need to be changed every 3-6 months, while the condition of mechanical filters should be checked at least once every 2 months.
In most cases, to purify water in garden ponds, they use flow or pressure cleaning systems, which are driven by pumps included in the kit or supplied separately. Water is sucked from the pond and sent to a filter, where it is purified and then returned to the pond. Water flows into cheaper and less efficient flow filters by gravity, while into more expensive and efficient pressure filters it is pumped under pressure.
Powerful pond filters consist of several blocks located in a common casing. One of them - sterilizer(an ultraviolet lamp that irradiates water, killing microorganisms and blue-green algae in it). The main part of the system is three-stage filter. In its first compartment, the water is preliminary purified from leaves and other large contaminants. As a result of this process, the water is enriched with oxygen. The second stage of purification involves the biological decomposition of ammonia - a product of the breakdown of organic bacteria into harmless nitrogen compounds. At the third stage, the remaining ammonia is absorbed by a special substance, after which the water flows back into the reservoir.
Filter selection
You can determine which filter is needed based on its maximum performance or the performance of the pump that is included with the filter. A pond without fish should be completely pumped in 2 hours, and with fish - in 1 hour. Thus, by calculating the approximate volume of the pond in liters, it is easy to determine the models that suit you. For effective water purification in a swimming or stocked pond the filtration system must operate continuously for 24 hours(only in a decorative pond is filtering allowed for 6 hours a day).
Can be used to purify water from organic and biogenic elements, as well as to control the proliferation of protozoan algae. chemical and biological preparations. The use of the latter does not affect the established biological balance in the pond and in most cases they do not pose a threat to plants and living organisms. With the help of biological products, you can suppress the growth of microalgae and stop water blooms (for example, liquid extract of barley straw is used). There are also all kinds of drugs to support the immune system of fish in cold water, increase the activity of processes in the pond in winter and early spring, etc.
Chemicals are used to restore the acidity level of a reservoir, saturate the water with oxygen, and dissolve algae. When using them, you must strictly adhere to the dosage, since in excessive doses they are harmful to fish, plants and humans. Their use can lead to disruption of the biobalance of the pond.
Filter Fountain Pump
If you install a fountain pump with a mechanical filter and an ultraviolet lamp at the bottom of a decorative pond to suppress harmful bacteria and algae, then in this case you can do without using an external filter for water purification. Available models of filter fountain pumps can be used for reservoirs with a volume of up to 5000 liters. To protect against clogging, pumps are installed on a concrete or metal base at the bottom of the reservoir. They are connected directly to the electrical network, so when choosing, pay attention to the length of the cable and provide a residual current device in the network. Naturally, such a pump must be turned off when servicing the pond.
Pond aeration
Enriching water with oxygen is extremely important for the flora and fauna of an artificial reservoir. The air supply helps keep the water clean and clear, allows fish to develop normally, prevents the proliferation of harmful microorganisms, regulates the growth of algae, ensures water circulation from the bottom to the surface, eliminating unpleasant odors. In winter, aerators work as deicers and contribute to the formation of an unfreezing water surface.
Two types of devices are used. Diffuser bottom aerators consist of a compressor installed on the shore and diffusers connected to it by flexible hoses at the bottom. This technique is very effective, but it does not create a water pattern on the surface. And here floating aerator fountains In addition to clean water, they bring aesthetic pleasure. Moreover, you can order several replaceable fountain heads. Such aerators do not need to be installed; they float on their own.
Wintering a stocked pond
In autumn, fish begin to prepare for winter and store fat. When the temperature drops, it sinks to the bottom of the reservoir and stops eating. During this period, you should not feed the fish, since the abundance of uneaten food leads to water pollution. From mid-autumn to mid-spring, the water in a stocked pond may not be filtered, so it is necessary to provide for the possibility of turning off the filtration equipment.
An important question remains aeration of water. The main danger for fish in winter is the lack of oxygen and the accumulation of carbon dioxide under the ice. To winterize such a pond, the water aeration system is not turned off for the winter. With its help, the water is enriched with oxygen, and carbon dioxide, formed during the rotting of leaves, algae and other organic matter, freely comes to the surface. As an alternative, stocked ponds can be equipped with a de-icer that prevents ice from forming on the surface. A submersible pump can also be used. It is placed 20-60 cm below the water surface. It works for itself, as a result, moving water does not freeze. The main disadvantage of all these methods is a sudden power outage, which is why the reservoir needs attention in winter.
A properly selected and high-quality pond filter is an indispensable part of the water system, designed to clean the reservoir from harmful substances or pathogenic microorganisms. Such a device for purifying pond water differs not only in design features, but also in power and cost.
If an artificial reservoir begins to bloom and, as a result, completely loses its attractiveness, then most likely the biological balance in the water system has been disrupted. The water system can be restored through purification and subsequent filtration and aeration processes.
Under natural conditions, a flowing reservoir periodically renews the aquatic environment, and stagnant pond waters most often quickly turn into swamps. Artificially created ponds require regular and proper maintenance, and water transparency can be ensured by mechanical cleaning and proper arrangement.
Do-it-yourself water filtration allows you to balance the composition, and also has a positive effect on pond flora and fauna:
In the process of arrangement, it is necessary to take into account the location of the reservoir, as well as its volume and purpose. When choosing a location, you need to ensure systematic shading and the absence of closely spaced deciduous plantings. It is especially important to take into account such requirements for reservoirs with fish and expensive ornamental aquatic vegetation.
Usually, all popular and modern filtration systems are quite large, but it is recommended to consider the features of the location and installation of such devices at the pond design stage.
| Volume of water in the reservoir | Advantages and disadvantages | Popular models |
|
| Up to 8 cubic meters | Submersible pump with side outlet and pressure filter | Aeration, mechanical and biological treatment, built-in UV lamp, ability to bury pressure filter for the coastal zone with artificial stone decoration | Ready-made Heissner kit |
| From 8 to 35 cubic meters | Based on submersible pump | A pressure or flow filter located on the shore, as well as a submersible pump installed in the deepest place. Connecting the filter and pump with a special spiral hose | Ready-made kits from manufacturers Heissner, FIAP and OASE |
| cubic meters | Ready-made kit “SK-500” |
||
| cubic meters | For domestic use, the universal unit effectively removes the smallest contaminants and is capable of working with both a surface cleaner and a flow filter. | Compact-Sieve filter system |
|
| From 70 to 120 cubic meters | At the planning stage, you can use the option of bottom water intake and side skimmer | Compact, professional, highly efficient filtration system is located entirely outside the pond and is low maintenance | Ready-made kit “SK-502” |
| From 70 to 120 cubic meters | To equip a ready-made pond, a mechanical cleaning filter with a pond pump is used | High efficiency rates due to the large area of the filtration elements, easy connection to a conventional pond pump | OASE filtration kit |
The most difficult thing is to choose the right filter system if you plan to breed fish in an artificial reservoir:
When choosing equipment, special attention should be paid to the following characteristics:
A properly selected submersible model can carry out high-quality cleaning in no more than an hour and a half. For most artificial reservoirs, the best option is pumping equipment with a low pressure level and significant capacity. The gravity-free gravity pump is universal and, accordingly, in demand.
A homemade filter for a pump is quite easy to make. A gentle sludge system can be implemented using the following recommendations:
Filter materials are loaded layer by layer into a basket container. The siphon and hose are secured using plumbing sealant. The hole for installing the siphon must be drilled in the side of the basket, which will allow water to flow freely into the filter layers. All connections between the siphon and hose with the body must be thoroughly coated with silicone sealant, after which the pump is immersed in water and the device is connected to the electrical network. For safety reasons, the electrical outlet must be protected with a waterproof rubber or plastic casing.
To independently create a filter used in ponds with fish, you will need two medium barrels, as well as adapters, main connections and taps. Water is taken from the bottom of the pond and, under the influence of a pump, is delivered to the filter. Passing through several layers of cleaning, the liquid returns by gravity to the reservoir. The following can be used as a filtration substrate:
With minimal implementation costs, such a system is characterized by a high degree of reliability and sufficient durability.
The choice of filter equipment is greatly influenced by factors such as the size and depth of the pond, the presence of living inhabitants in the reservoir and climatic conditions. For the most effective filtration process, you need to correctly determine the performance indicators of the pump, as well as its power, which will allow you to purchase not only high-quality, but also durable equipment.
One of the most important conditions for maintaining a stable pond ecosystem in the country is, of course, water purification.
With the help of pumps and filters, the water in the artificial reservoir remains clean. You can buy them in stores or make them yourself.
To solve this problem, it is necessary to provide a system of pumps and filters when designing an artificial reservoir.
Many owners try to carry out landscaping at their dacha in full - in the case of a pond, this means building a reservoir with their own hands, decorating the banks, installing filters, and maybe a fountain. To maintain the ecosystem of an artificial reservoir in a clean state, the water must be promptly purified using pumps and filters. You can choose a filter in a store or make it yourself. Often, there are simply no filters in ponds at the dacha - this is explained by the fact that the size of the artificial reservoir is quite large, fish and plants are quite capable of maintaining the necessary balance, and the amount of algae per volume of available water does not exceed the established standards. When more algae appears than necessary, they can be controlled using chemicals. Only recently has pond filtration become a necessity, and there are reasons for this.
The choice of filter is influenced by a number of factors: the size of the reservoir, its depth, climate of the area, living creatures in the pond, etc.
To choose the right filter for a pond at your dacha, you need to take into account many factors, namely:
This kind of improvement, like a self-made fountain, is not very difficult to complete. As a rule, the main difficulties await pond growers when selecting filters for purifying an artificial reservoir where there are a large number of fish. Gradually, the living creatures in the pond grow, and accordingly, the amount of waste products of fish or other representatives of the animal world and the need for oxygen increase. Therefore, for a “living” pond it is necessary to select with a small margin of productivity. Waterfalls and cascades will help saturate the water with oxygen; you can use a fountain. During circulation, the water will become more enriched with oxygen, and then, already saturated, will return back to the reservoir.
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Pressure filters can be installed below the water level of the reservoir.
A pressure filter is considered the simplest and most economical way to design a cleaning system. On the top cover there are device controls and inlet/outlet connections. Water is passed through it under pressure and purified in three stages: first - a mechanical purification stage, then - a biological one, and finally the water is subjected to UV irradiation.
These filters can be hidden in the ground, masked with artificial plants or decorative stones.
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A gravity filter with good performance and reliability requires very little maintenance. It is a tank equipped with various cleaning elements - sponges, meshes, filters. Non-pressure devices are usually used for large or medium-sized reservoirs (up to 200 m3) - they are located higher than the water level.
The main disadvantage of flow filters is that they are quite difficult to decorate in pumping systems, since they cannot be allowed to be buried in the ground by more than a third of the height of the housing.
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Of course, you can buy a filter for a pond in a store, but if the pond is small in size and not inhabited by fish, it can be successfully cleaned using a filtration system made from scrap materials. To do this, you will need a low-power underwater pump and a plastic basin.
In the lower part of the pelvis, trying not to touch the bottom, make a horizontal hole with a width of about 20 cm and a height of approximately 10-12 cm. A flat stone must be inserted into the opening (the “protrusion” from the pelvis should be about 15 cm). The bottom of the basin is filled with cement-sand mortar to the level of the upper plane of the stone, then it is smoothed out so as to create a drain to the cascade, to the first level. After the solution has hardened, the surface can be treated with a special waterproofing compound.
The structure is installed on the top of the cascade. Next, four stones with a height of 4-6 cm are placed in the basin, and everything is covered on top with a piece of stainless steel or plastic. Fine crushed stone is poured, padding polyester is laid on it, after which the hose from the pump is inserted. The upper, visible part is decorated with large stones or pebbles.
From the pump, which is located at the bottom of the pond, water is supplied through a hose into the basin. Then it seeps through layers of crushed stone and padding polyester and flows down a cascade back into the reservoir. As they become dirty, the synthetic padding pads are replaced and the crushed stone is washed.
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How possible is it to build a fountain in an artificial pond at your dacha with your own hands? In a technical sense, this is not particularly difficult. Submersible pumps that are commercially available come in a fairly wide range, and choosing something to build a fountain is not difficult. The most common way to carry out landscaping is to purchase a ready-made kit, which includes a submersible pump, a sprayer and a tee with a flow regulator. The device is powered from the network or through a transformer. To prevent the pump from coming into contact with the bottom, it is installed on a brick or concrete block, and the pipe with the sprayer must be fixed strictly vertically.
After these manipulations, all that remains is to turn the switch to make it work. If the water jet is too high or wide, it can be adjusted. prefer to install with decorative cladding. There are many different types of it on sale. It can be made of stone, ceramic, bronze, fiberglass, etc. Decorative cladding must be frost-resistant.
The submersible pump is installed on a stand so as not to pick up sediment from the bottom.
The submersible pump must be installed on a stand that will prevent it from picking up sediment from the bottom. Aquatic plants must be at least 50 cm away from the fountain jet. If you connect a homemade filter or some additional device, for example, a waterfall or another fountain, you need to take some points into account. Installing pipes with a small cross-section or a fountain located at a considerable distance will certainly lead to less efficiency.
For placement in artificial reservoirs - for example, ponds created with your own hands at the dacha - you can make your own filter design in the form of a submersible device, with a volume from 0.5 to 3-5 cubic meters. and a depth of 0.8 m. This homemade filter design is both quite reliable and cheap. Thus, installing it in a pond at the dacha is not a hopeless undertaking.
The design of a homemade filter is simple to implement. The aquarium pump, taken as a basis, is equipped with a filter element whose power is an order of magnitude greater than the standard one in terms of absorption area. For the frame of the device, you can take a plastic bucket.
The aquarium pump allows you to supply and spray air, and it is also reliable in operation.
1. Aquarium pump. Those who are interested in aquarium farming may accumulate several pumps in the process. You can consider a design using the Polish brand AQUAEL FAN-2 pump. This pump has quite good characteristics - it allows you to supply and atomize air efficiently, create the necessary flow, and is reliable in operation. But as a cleaning filter, the pump’s operation is still conditional. A small filter does not allow quality water preparation and requires frequent washing. The external circuit of the pump consists of two parts: a housing with pipes, a vane motor and a stroke regulator, and a housing for the filter element.
The pump is powered from a 220V network, power consumption is 7.2 Watts.
2. Filter frame. A bucket with a lid is used for the filter housing. A plastic ten-liter bucket is perfect. It must be strong enough to withstand a load of up to 15 kg. The color of the bucket should be black or another color to match the bottom of the reservoir, for less visibility.
The plastic case will need some modification:
3. Filter element. A variety of materials can be used as a filter element - foam rubber, padding polyester, and even fibrous materials that are used for thermal insulation of refrigerators. Foam rubber is still considered the most affordable. Of course, it is more practical if you use purchased foam rubber, 50mm thick, but you can also use large pieces from packaging.
September 23, 2012
“Bloomed!” This exclamation from the owners of garden and summer cottages is not always enthusiastic. The owners of green areas with a pond pronounce this word with sadness and despair. The water in a pond, swimming pool or artificial stream is not always fresh and clear: sometimes it “blooms,” but the owners are less pleased with this bloom than a flowerbed sparkling with bright colors.
Water in stagnant bodies of water is mainly susceptible to blooming. Various microalgae cause the effect; the color of the cloudy pond depends on the variety of these uninvited guests: green, yellow or bluish.
Microalgae exist in any body of water, but they begin to multiply intensively under suitable conditions. For example, if the weather has been hot for a long time, if the owner of the pond was too lazy to remove the leaves that had fallen on the surface of the water in time. The reason may also be a strong love for the inhabitants of the pond - the owner of the pond may feed the fish too actively, and the remains of food and vital activity of the aquatic inhabitants begin to decompose in the water.
An abundance of rain and the accumulation of silt at the bottom of a pond can also cause a disruption in the natural balance in the water. Therefore, the first and main condition for maintaining the purity of water is regular cleaning.
Some summer residents and owners of garden plots have a philosophical approach to their ponds: “blooming” is a natural process, so in a couple of weeks the water will clear itself. And why spend money on strange devices if I personally am not sure what if my fish die after this cleaning? Or will your favorite water lilies begin to rot?
Such fears are unfounded. Modern filters are absolutely safe for the inhabitants of your pond. Moreover, many filtration systems enrich the water with oxygen, for which both fish and water lilies will thank you. Oxygen will prevent water from blooming, so the operation of filters will also help maintain the balance of the aquatic environment.
Today there are a huge number of devices for water purification in artificial reservoirs. The units differ in the method of exposure and quality of cleaning. Filters are selected depending on what tasks the owner will assign to the device:
Almost all filtration systems are now “multi-machine”. Smart technology saves both our energy and time (prices for filters, of course, vary, but we’ll talk about them a little lower). Therefore, filters are now generally divided into two categories - flow and pressure.
Flow filters are designed to purify reservoirs whose volume does not exceed 300 cubic meters. The figure may decrease if there are fish in your pond.
Flow filters only work in conjunction with a pump. The operating principle of flow filters is based on the fact that water passes through a container in which it is cleaned of debris and insoluble particles. Filter material (porous, such as a sponge) traps algae and some harmful organic compounds. Capsules with beneficial cleaning bacteria can be located in a separate filter module (they allow you to reduce the amount of phosphates and nitrogen in the water, and remove excess waste products from the inhabitants of the pond). In addition, the device can house a chamber with ultraviolet lamps for bactericidal water purification.
Pressure ones process a smaller volume - from one to 60 cubic meters, but with their help purified water can be supplied two or even five meters higher from the point where the filter is placed. This option is considered an ideal solution for streams and small waterfalls.
A pressure filter is a more complex device compared to a flow filter. But it cleans according to approximately the same principle: water is passed through sponges, then enters sterilizers or biological modules.
In a pressure filter system, water circulation is organized using an electric pump. It is installed at the bottom of the pond. Purified water is supplied to the required height, from where it flows down in the form of a stream or waterfall, gurgling and sparkling with crystal purity.
Ultraviolet treatment allows you to delicately (though not quickly) clean a pond of polluting bacteria and microalgae. A UV emitter is often built into filters, but it can also be purchased separately.
The effect of using the emitter will not appear immediately, only after 5-10 days. The UV emitter does not require much space and has no installation difficulties; it is placed on the shore. Another advantage of this unit is its cost - lower than that of a full-fledged filter.
Many sellers of filtration systems for ponds offer their customers to purchase a skimmer in addition to the main purchase. What it is?
A skimmer is a device with which the surface of a reservoir is cleaned of large debris. Using a skimmer, you can promptly remove leaves and small twigs that fall into the pond during strong winds. They will not sink to the bottom and will not turn into food for microorganisms, which means your pond will have less chance of blooming.
The skimmer serves as a kind of pre-filter; it also purifies water and facilitates the operation of flow or pressure systems.
One of the additional conditions that may be especially important for aesthete gardeners is the possibility of deepening the filter. After all, summer residents with a heightened sense of beauty may not like the presence of a strange-looking box on their site. And here - grace! I buried the filter up to the top cover, sat a ceramic frog on top and let it monitor the operation of the device! You can organize a house for a gnome or decorate it in some other way. Amateur designers have a lot of imagination! You just need to check for the possibility of deepening when choosing a filtration system.
Prices for filters for ponds depend on the complexity of the units. If the device is designed for a small pond volume, is not ready to work with reservoirs populated by fish and is not burdened with additional blocks with UV light or a chamber with balls that help the growth of beneficial bacteria, its price will be about 10 thousand rubles.
Of course, this is the bare minimum. Powerful filtration systems will cost retail customers from 50 thousand rubles. The upper bar is practically unlimited. The more capabilities a filter has, the higher its cost, so it’s up to you to decide and count too.
© Green-portal.ru, photo: www.oase-teichbau.de
When creating or planning a film pond (see article " "), do not forget about installing a filtration system. Otherwise, you will experience rapid growth of algae during the warm season, pollution from fish waste, pollen and leaves falling into the pond and decomposing at the bottom. In this article we will look at the most common and effective filters for decorative artificial ponds.
the pressure filter is buried in the bank and can be decorated
System advantages:
Effective filtration of upper layers
Active aeration and sterilization of water
Impurities that enter a reservoir do not have time to sink to the bottom and begin to decompose
Select taking into account the intended use of the reservoir (it is necessary to increase the productivity of the system by 2 times when planning to launch fish, and by 3 times - koi carp)
Select the maximum diameter (supported by the filter and pump) - in this case, friction losses will be less and the filtration efficiency will be higher. Be sure to cut off the excess part of the fitting (filter and pump) of smaller diameters, otherwise the filtration efficiency will be significantly reduced!
