Question 4
- Describe how specimen A is used on a fish farm. [5 marks]
- List five water quality parameters which specimen J could be used to measure.[5 marks]
- Describe how specimen K is used in a fish pond. [5 marks]
Observation
Many candidates could not give satisfactory answers to this question. Ambiguity in answers and wrong spellings were common as many could not effectively give a sequential description as required in 4(a) and 4(c). Many candidates could not list the water quality parameters as required in 4(b).
The expected answer is as follows:
(a) How specimen H (water pump) is used on a fish farm
- Place water pond on flat a surface
- The hoses are connected to the pump
- One end of the hose is dipped into the water to be drained
- The other end of the hose is placed / positioned for water discharge
- The machine is switched on
- Water is drained or pumped as desired
- The pump / machine is switched off after usage
- Hoses are disconnected
(b) Water quality parameters that specimen J (Water test kit) could be used to measure
- Conductivity
- Dissolved Oxygen
- pH/ alkalinity/ acidity
- Temperature
- Turbidity/ transparency/ total dissolved solids
- Ammonia/ nitrate
- Salinity
- Hardness
(c) Description of how specimen K (Secchi disc) is used in a fish pond
- The rope is held
- The disc is lowered slowly into the water
- The depth at which the disc is no longer visible is noted
- Stop lowering the disc
- Pull the disc out
- Take the reading
- Repeat the process
- Find the average of the readings taken