|Better Farming Series 29 - Freshwater Fish Farming: the Pond (FAO, 1981, 43 p.)|
|Building a bigger pond|
97. If you use a plastic or metal pipe for the outlet of your pond, you can make it better by putting an upright length of pipe on the end of the outlet using an L or a T piece like the ones in the drawing. Close the T piece with a plug as shown.
L and T pieces
98. Put the L or T piece and the upright pipe on the end of the outlet outside the pond, but protect it so that it cannot be reached by animals or other people.
99. The top of the upright pipe should reach about 3 to 5 centimetres above the water- level of your pond. If the water rises above this level, it will overflow from the upright pipe.
Water level in pond
100. Tie the upright pipe to a pole which has been pounded into the ground so that it will not slip down and let the water out of the pond before you want it to.
101. When you want to let out the water, untie the upright pipe and push it down. The water will then flow out of the pond.
Push down the upright pipe
102. There is still another way to let water out of your pond, using a siphon. You will learn how to use a siphon in items 114- 124.