Question 1
Study specimens C and D carefully and answer the questions that follow.
(a) Name the water quality parameter measured by each of specimens C and D. [2 marks]
(b) State the optimum range for the water quality parameter measured by each of specimens C and D in fish pond. [2 marks]
(c Describe how specimen C is used to take measurements in a fish pond. [5 marks]
(d) Mention three water quality parameters that could be measured in a fish pond. [3 marks]
(e) Name three other items that could be used to measure water quality parameters in a fish pond. [3 marks]
Observation
In part (a), majority of the candidates could not name the water quality measured by each of specimens C and D.
In part (b), majority of the candidates did not state the correct optimum range of water measured by specimens C and D.
In part (c), majority of the candidates could not describe how specimen C is used to take measurement in a fish pond.
In part (d), majority of the candidates could not mention three other water quality parameters that could be measured in a fish pond.
In part (e), majority of the candidates could not name three other items that could be used to measure water quality parameters in a fish pond.
The expected answers include:
1(a) C – Temperature
D - pH / acidity / alkaline
(b) C – Temperature: 24 - 320C
D - pH 6.5 – 8.5
(c) - Hold the tip of the thermometer at the upper end
- Shake the thermometer ( to return the meniscus to zero)
- Dip the mercury and of the thermometer into the pond water / partially submerge
- Keep in the water for few seconds / some time
- Bring out / withdraw the thermometer
- Raise the thermometer to eye level
- Take the reading of the lower meniscus
- Repeat the process at several point in the pond
- Find the average
(d) - Dissolved oxygen / DO
- Turbidity / dissolved solids
- Conductivity
- Salinity
- Ammonium (NH4)
- Nitrous Oxide (NO)
- Nitrite (NO2)
- Nitrate (NO3)
- Hardness
- Transparency
(e) - D.O meter
- Litmus paper
- Secchi disc
- Conductivity meter
- Turbid meter
- Salinometer
- Hach kit / water test kit