Construction, Care and Management of a Backyard Fish Pond project
Planning the site and type of fish farm
Proper selection of a site is probably the most important factor in the success of a fish farm. There may also be conflicts concerning land and water use which need to be resolved.
The quality of soil influences both the productivity and water quality in a pond. However, it must also be suitable for dike construction. To determine soil suitability the two most important properties to examine are soil texture and porosity or permeability.
Three (3) ways one should follow to predict whether the soil will be suitable for pond construction are A) the “squeeze method” B) the ground water test and C) the water permeability test.
A). SQUEEZE METHOD (FIGURE 1)
1. Wet a handful of soil with just enough water to make it moist (Figure 1A),
2. Squeeze the soil (Figure 1B) and if it holds its shape after opening the palm of your hand (Figure
1C), the soil will be good for pond construction.
B. GROUND WATER TEST (FIGURE 2).
This should be performed during the dry period in order to get reliable results:
a). Dig a hole with a depth of one meter
b). Cover it with levels or one night to limit evaporation
c). If the hole is filled with ground water the next morning a pond could be build.
d). If the hole is still empty in the next morning, no problem will occur as a result of high ground water levels and the site will perhaps be suitable for pond fish farming. You should test the water permeability.
C. Water permeability test:
a. Fill the hole with water to the top
b. Cover the hole with leaves
c. The next day the water level will be over due to seepage. The dikes of the hole have probably become saturated with water and might hold water better now.
d. Refill the hole with water to top
e. Cover it once more with leaves. Check water level the next, if the water level is still high, the soil is impermeable enough and is suitable for pond construction.
g. If the water has disappeared again, the site is not suitable for fish farming, unless the bottom is first covered with plastic or heavy clays.
The Land Contour, and especially the land slope. Determine the way to build pond. The slope of the land can be used for the pond’s drainage at harvest.
Totally flat land and a hilly terrain with a slope of more than 2% – 4% are unsuitable for pond construction so all sloped are between 2% and 4% can be used for pond construction.
The availability of good water quality is important for all fish farming systems but water quantity is of even greater importance for land based fish farming systems.
The water temperature is an important criterion in assessing whether the fish species selected can be raise. A water temperature between 20 °C and 30 °C is generally good for fish farming.
Types of AQUACULTURE farm
Fish farming may range from large scale industrial enterprises to ‘backyard’ subsistence ponds.
Farming systems can be distinguished in term of INPUT LEVELS
In extensive fish farming, (economic) inputs are usually low. Natural food production plays a very important role, and pond productivity is relatively low.
In Semi-intensive fish farming a moderate level of inputs us used in fish production is increased by the use of fertilizer and/or supplementary feeding.
In Intensive fish farming a high level of inputs is used and the ponds are stocked with as many fish as possible. In this system the high feeding costs and risks, due to high fish stocking densities and thus increased susceptibility to diseases and dissolved oxygen storage, can become difficult management problems.
The vast majority of freshwater fish are raised in ponds. Water is taken from a lake, bay, well or other natural source and is directed into the pond. The water either passes through the pond once or is discharged or it may be partially replaced so that a certain percentage of the total water in a system is retained and recirculated.