Page 62 - fish_farms_curriculum

6.2.3. Sand Filter

It works by ensuring that the water collected from fish tanks is passed through layers which

contains sand and gravel grains of different particle sizes in a pressurized system and solid
waste remains in these layers. Depending on the size of the system, sand and gravel should be

washed reversely several times a day with the water in the system, and the polluted sand and
gravel should be rinsed out (with the help of the valves in front of the filter), and the solid

wastes kept in the filter should be discharged from the filter. Otherwise, the pressure in the

filter will increase and it may cause clogging of the system.

Picture 24. Sand Filter

6.2.4. Sedimentation Pool

It is mostly used in enterprises with large water mass and intensive fish production. The water
from the fish tanks is collected in a relatively deep pool, and the water is re-collected from the

surface of the opposite side of the pool. As the water flows from one side to the other,

unwanted solids settle to the bottom of the pool. In this pool type materials such as sand,
gravel, etc. can be used for particle retention in terms of natural filtration. As seen in Figure

8.8, placing barriers to allow water to move up and down after the water inlet will increase the
amount of solid wastes to be retained. Since the solid wastes accumulating at the bottom of

the pool will deteriorate the water quality over time and must be cleaned continuously, its use
in geothermal systems is relatively low.

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