© Hope Mwanake 16th August 2010
Baobab Trust
Mtopanga Organic Farm
A Guide to fish farming
Site Selection
 Areas without trees, rocks and termite hills
 No flooding during the rainy season
 Clay soils with little water permeability
 Near a water source
Pond Construction
 Suitable size 2-10 ha, rectangular
 Proper layout of the pond, 10 by 20m wall has a base of 3.25m
 Should have an outlet pipe, inlet pipe and an overflow pipe
 Small ditch (30 by 30 cm) dug along the middle line of the walls and filled with
good clay to prevent seepage of water underneath the walls.
 Top soil should not be used for wall construction
 Material from inside wall to be wetted and tightly packed every 20 cm of height,
depth 80-100 cm
 Pond walls sloping (Height: Width, 1:1 inside, 1:1.7 outside)
 Wall crest 80 cm wide
 Bottom of the pond sloping towards the outlet (2-3 ppt)
Pond Fertilization
 Fill your pond with water using a small ditch from the water source to the inlet or
a hose pipe tied at the tap to the pond.
 Manure should be mixed with water and equally distributed over the water surface
or placed in a sack and tied somewhere in the pond and left to float inside the
water.
 3kg of either poultry, pig or cattle manure should be added per week
 The water will start to turn green in 2-3days
 Simple test to be sure that the water is green enough, put your arm in the water up
to your elbow, if you are just able to see the ends of your fingers then the water is
green enough.
Pond Stocking
 If your pond is 15 by 15 m (225m2), 450 baby fish are needed
 This is your area multiplied by two
 Stock your pond with baby fish which are 5-6 cm
Pond Feeding
Feed your 450 fish with tilapia pellets
 500-900g of food everyday during the 1st month
 900-1200g of food everyday during the 2nd month
 1200-1600g of food everyday during the 3rd month
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1600-2000g of food everyday during the 4th month
2000-2700g of food everyday during the 5th month
2700-3500g of food everyday during the 6th month and until the time that you
harvest your fish.
Important notes
o Prepare all the food for one day’s feeding at the same time
o Feed your fish 3 times during the day
o Always try to feed your fish at the same times everyday e.g. 7am, 12pm and 17pm
o You must watch them when they eat to learn how much they need
o Feed them in the shallow part of the pond so that you can see them eat
o If you see that they do not eat all their food give them a little less the next day
o If you see that they eat all their food quickly give them a little more the next day
o Feed them at the same place everyday
o If you give them too much food, the uneaten will stay on the bottom, too much
uneaten food on the bottom of the pond will take the air out of the water
o Your fish will not grow if they lack oxygen. If you see your fish gulping for air
make sure you add more fresh water making sure it falls with pressure forming
bubbles and form
Taking care of your fish
 Watch them carefully to see that they are healthy and swimming strongly
 Remove any dead fish floating immediately and change some of the water
in your pond
 Open the inlet to let in new clean water and let old water drain out of the
pond at the overflow. Do this for 2-3 hrs each day for several days until
your fish are well.
 If it is too hot, do not feed your fish too much or put too much fertilizer
since there will be too little oxygen in the water for your fish to breath
 If your fish are gasping for air at the surface, feed them less and put no
fertilizer for several weeks
 Let new water into the pond with a splash to bring more oxygen into the
water to make the fish breath easily.
 If other things are wrong with your fish that you do not understand, stop
feeding them and stop fertilizing. Change some water in your pond
everyday for several days.
 After several days if your fish are still not well and are not eating well or
gasping for air and are not eating well or gasping for air and are not
swimming strongly ask help from any extension agent or fish culture
station.
Harvesting your fish
a) Harvesting without draining the water
 If you do not have enough water to fill your pond again and if you want to harvest
only part of your fish. Use a seine net.
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A seine net with a mesh of 3-3.5 cm catches big fish only and allows small fish to
escape while a seine net of mesh 1 cm catches all fish
You will need several people to harvest with a seine net.
Start at the deep end of the pond and pull the seine net slowly towards the shallow
end then lift the net out of the water with the fish caught.
Cast nets and lift nets are easier to catch the fish while they are eating and they
also keep the biggest fish while the small fish are left in the pond.
b) Harvesting by draining all of the water
 This is the best since it ensures all the fish are caught and the pond can be cleaned
and limed
 While the pond is being drained, use baskets or hand nets to take fish out of the
water
 After all the water has been drained carefully collect all the fish gathered in the
small pools
c) Harvesting by draining part of the water
 Let the water flow out through the outlet and harvest your fish with a seine net
 Take only the big fish and retain the small fish
 When harvesting is finished let water flow back into the pond until it reaches the
level of the overflow pipe
After Harvesting
 Sell your big fish
 Put the baby fish back into your pond ready for next season harvesting
 Sell some of your small fish to another farmer
 Keep the baby fish in a nursery, in a pen of split bamboo in another pond that is
full of water, in the corner of a big pond separated by a net or keep them in a
small pond
 Take good care of your baby fish, they will stay alive longer if they:
o are out of the sun
o have fresh water running with plenty of oxygen
o are fed a little food each day
 If you have too many baby fish dry them, grind or pound them and mix them with
rice barn to feed your big fish
Begin again
 If you have drained all the water from your pond, clean the bottom of the pond
 Remove some of the excess murk and pour it in your garden
 Spread the remaining murk equally on the bottom of your pond and at the banks
 Lime your pond thoroughly to disinfect it and to neutralize the pH
 Do not let your pond bottom become too dry because it may crack
 Leave it for three days while you repair the banks and cut the weeds and grass on
the banks
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If there are any water leaks in the banks or around the inlet, outlet or overflow,
stop them by packing with good clay soil
Fill the water
Fertilize
When the pond is green enough again stock with healthy baby fish which are
about 5-6cm
In about 6 months you will be able to harvest another crop of fish
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