The first step in Fish pond construction is getting a good site for your pond. Choosing a good site for your pond is a step that partly determines the success of your farm because, A good site offers greater chances of survival for your fishes. Fish pond construction is more than just land excavation, It often requires a little technical analysis
The first step in Fish pond construction is getting a good site for your pond. Choosing a good site for your pond is a step that partly determines the success of your farm because, A good site offers greater chances of survival for your fishes.
Therefore, before starting a fish pond construction, You must know how to play around with these factors;
- Source of water supply to the pond
- The soil type of your pond site
- Topography of the land
However, It is important to know that having an ideal site for pond construction may be difficult. But, having like 2-3 of the factors listed above in your pond location is a good start.
Site selection for fish pond business
Proper selection of site as i said earlier is probably the most important factor in the success of a fish farm. However, aside from these ecological factors listed above, You also consider other factors like safety of your farm, nearness to home, distance from a source of potential pollutant. All these and many other factors at your own discretion have to be considered first.
Source and quality of Water
Water is very important in fish culture. It can be obtained from direct or indirect run offs like streams, spring, lakes, rivers, reservoirs, irrigation canal, well and bore holds.
However, Where river or stream water is not reliable, conservation dams or tanks may be built to store water. In any case, It is important to always determine the quality and quantity of the water available for your farm.
Thus, when considering the quantity of water, a constant supply of water is needed not only to fill the pond, but also to make up for the losses caused by seepage and evaporation. Therefore, You make sure that the source of water supply to the pond will be available and adequate all-year-round to the pond.
In addition, the quality of water such as pH, Salinity, temperature, pollutability and potential for growth of plankton.
As a rule, when using water from Tap; such water must be exposed to the atmosphere for minimum of 48 hours to ensure that the chlorine content vaporizes off. It is also important to always check the alkalinity or acidity of the water. Also, Investigation of the amount and seasonality of water sources, as well as their position in the field regarding possible pollution is very important in site selection.
Water temperature of between 27oC to 30oC is generally good for fish farming.
Variation in water salinity is also an important environmental factor which must be considered. Some species can withstand a wider salinity range than others: e.g. tilapia and catfish can withstand a wide range from fresh to seawater while carp can only tolerate freshwater.
The quality of soil influence both productivity and water quality in pond. Generally, when considering the quality of soil for Fish pond construction; Soil texture (Particle size composition),porosity or permeability (ability to let water pass through) and fertility (ability to support life of water weeds and zoo plankton) must be considered.
2 ways to determine good soil type for fish pond
- Squeeze method; Take a bunch of the soil from the proposed site in a wet hand and squeeze. If the sand stays together after you open your hands, the soil is good for a pond. The reverse is the case if the sand fails to stick together. In addition, another parameter you can check with this method is the texture of the soil type. Coarse soils is not good for a pond since they can hardly retain water nor support vegetation.
- Water Permeability test; In this technique, You dig a pit of about one meter deep. You pour water inside it overnight and cover with fresh leaves to reduce water by evaporation. If in the morning, there is no water left in the hole, It means water have been lost by seepage. Therefore, the soil is not good for fish pond.
In summary, when considering the type of soil for your fish pond, Clay and Loamy soil will always be preferred. A good soil for fish farm should at least contain 25% of clay.
Topography of the land
The land contour and especially the land slope, determine the way to build pond. Irregular land, totally flat land and a hilly terrain with a slope of more than 2% to 4% are unsuitable for pond construction.
Percentage slope of a land can be calculated thus; The measure of the difference in elevation of two points (Rise) divided by the measure of the distance between the two points (run) x 100. That is, Rise/run x 100.
In addition, underneath pipelines, nearness to railways and industries may not be a good choice of land for your farm.
The next step to take after considering the site for your pond is to determine the type of pond you will like to build. However, You have to consider some factors that will help you decide the right pond for you. Some of these factors includes; Availability of land, capital, convenience, the stage of fish and other factors.
1. EARTHEN POND
In locating an earthen pond, land with gentle slope is selected and probably with a layout that take the advantage of the existing land contour.
Construction of an earthen pond is simple, it does not require a technical-know-how and its something you can do on your own. Pond may be dug into the ground, may be partly above and partly in the ground or they may be below original ground elevation.
However, Pond can be of any shape – rectangular or square. The mainstay of building a pond is to make sure water in-let and drainage is good. Inflow lines should be of sufficient capacity to fill each pond within 3 days. Also, if the source of water to your pond is a surface water, the incoming water is filtered to remove undesirable plants or animals.
More so, the slope and bottom is well packed during Fish pond construction to prevent Erosion and Seepage. Water loss from the pond should primarily be from the drainage. Consequently, a proper drainage is a characteristic of a good pond and should not take 3 days for complete draining. The side slope of the pond should be 2:1 or 3:1 slopes on all sides.
In addition, its is very important to remove external objects from the pond such as; Rocks grass, tree branches and other undesirable objects that may be on the dyke.
Pond Depth and Dykes
Depth should be 0.5 to 1.0 m at shallow end, sloping to 1.5 m to 2.0 m at the drain end; deeper pond may be required in Northern regions where the threat of winter-kill below deep ice cover exist. The Dykes should be sufficiently wide and high enough to prevent havoc that can occur from flooding. Planting of plants on earthen dykes makes it look like a natural habitat to the fishes and also as a source of food. However, dykes on the road sides is encouraged to be made of gravel.
Source of water
Depending on the site, You can choose to build any of these two types of ponds; Diversion pond or Barrage pond.
The diversion pond is built by bringing water from another source to the pond.
i. Embankment Pond: The dykes of an embankment pond are built above the ground level. A disadvantage of this type of pond is that you may need a pump to fill the pond.
ii. Excavated Ponds: An excavated pond is dug out of soil. The disadvantage is that you will need a pump to drain the pond.
iii. Partially excavated ponds with low dykes. Soil dug out from the pond is used to build the low dykes of the pond.
The barrage ponds are made by building a dyke across a natural stream.1 Therefore, the pond is a small conservation dams. The advantage of a barrage pond is that it is easy to construct.
However it is very difficult to control this system. It is equally difficult to keep wild fish out and a lot of food added to the pond will be lost because of the current.
Advantages of earthen ponds
- It does not require a great deal of experience to build.
- Earthen pond construction is cheap and cost effective.
- The pond looks like a natural habitat to the fishes.
- The earth encourages the growth of phyto plankton which can serve as food and drugs to the fishes.
Disadvantages of earthen ponds
- Requires a lot of land space to build.
- It is always situated in an open place which can expose the pond to invaders and thieves.
- External factors such as contamination and flood can easily affect the site because you have no full control of the pond.
- Disease outbreak is more difficult to spot and control.
2. CONCRETE PONDS (Homestead Pond)
Concrete pond as the name implies is made from concretes. There is no special way of building a homestead pond from earthen ponds. However, the difference lies in choosing the pond deep and the width. You have to take into consideration the extra measurement for the concrete when calculating the capacity of your pond.
But, to build a concrete fish pond that will last and devoid of errors, you will need a professional help. The floor of the pond have to be waterproof to minimize water loss by seeping. Also, Pipe for draining and overflow can be installed to drain and prevent overflow after a heavy rainfall.
This type of pond is popular in urban areas and remains the most popular type of fish pond.
Advantages of concrete pond
- You can easily control the system like the temperature of water, the pH etc..
- Site choosing is not a problem since it can be constructed on any type of soil.
- It does not require land capacity as that of earthen pond.
- The concrete pond can be used to grow all sizes and types of fish if the condition of growth are met.
- Monitoring of fish growth is easier and can support easy fish sorting (Separation of bigger from the smaller fishes).
- Predators and other external factors such as contaminants can be controlled easily.
- concrete fish pond is durable and does not require constant maintenance such as demudding.
- Diseases in the farm can be discovered and controlled easily.
Disadvantages of concrete fish ponds
- The pond is more expensive to build especially for a starter.
- If not properly treated after building, the chemicals can cause the death of fishes.
- Concrete pond is artificial.
3. Tarpaulin and rubber fish ponds
This is the most recently evolved type of fish pond in Nigeria. The tarpaulin fish pond has so many advantages over the earthen pond and the concrete pond.
Advantages of Tarpaulin/rubber ponds
- This type of pond is very easy to fix.
- It is cost effective.
- The pond is flexible and can be easily relocated.
However, to get the best out of a tarpaulin type of pond, there are factors you will have to consider such as; Getting a good and durable material from a trusted supplier and knowing how to fix the Tarpaulin yourself.2 This will reduce the cost of establishing your pond.
Summarily, You can get a good fish pond by selecting a good site, taking into consideration the topography, soil type and sloping. The pond building is best if you can control your water inlet, outlet and water lost by seeping.
Read also How to start a fish farm business