Name:
Water Quality & Microscope Lab
Unknown water Sample: _____________
Group members:
Microscopes – Examining your water Sample
1. Using the space provided below, draw what you see through the microscope. Under your
drawing you must note the magnification you are using as well as the unknown water
sample you are viewing.
2. Does viewing your water sample through a microscope tell you anything about the
quality of the water? Why or why not?
1
Name:
Calculating water quality
Use the tables below to fill out your Q-Value Chart for your unknown water sample.
1. Calculate % saturation for Dissolved oxygen
Note: Barometric Pressure for Regina is approximately 760mm
a. Record the dissolved oxygen reading you obtained last class.
b. Record the water temperature reading of your water sample from last class.
c. Using your temperature value and a barometric pressure of 760mm, record the
100% dissolved oxygen value (use Table 3 provided to your group).
Type equation here.
% 𝑠𝑎𝑡𝑢𝑟𝑎𝑡𝑖𝑜𝑛 =
Column
Reading
A
Dissolved
oxygen
(mg/L)
Example
Unknown
Water Sample
8.2 mg/L
𝐶𝑜𝑙𝑢𝑚𝑛 𝐴 𝑣𝑎𝑙𝑢𝑒 (𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑 𝐷. 𝑂. 𝑙𝑒𝑣𝑒𝑙)
𝑥 100
𝐶𝑜𝑙𝑢𝑚𝑒 𝐷 𝑣𝑎𝑙𝑢𝑒 (𝑠𝑎𝑡𝑢𝑟𝑎𝑡𝑒𝑑 𝐷. 𝑂. 𝑙𝑒𝑣𝑒𝑙)
B
Water temp
(C)
18.4 C
Example Calculation:
C
Atmospheric
pressure
(mmHg)
760 mmHg
D
100%
Dissolved
oxygen
(mg/L)
9.5 mg/L
E
Percent
Saturation
(%)
86%
8.2 𝑚𝑔/𝐿
% 𝑠𝑎𝑡𝑢𝑟𝑎𝑡𝑖𝑜𝑛 = 9.5 𝑚𝑔/𝐿 𝑥 100
2. Use the % Saturation value you calculated to determine your Q value for Dissolved
Oxygen
DO (% Saturation)
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
Q Value
0
5
12
20
30
45
57
75
85
95
100
95
90
85
80
Dissolved Oxygen Q Value for my
unknown water sample:
____________________________
2
Name:
3. Determining Q value for pH
pH
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
Q Value
0
1
3
5
8
15
25
49
54
75
88
95
85
65
48
30
pH Q Value for my unknown water
sample:
____________________________
4. Determining Q value for temperature
Temperature (C)
0
5
10
15
20
25
30
Q Value
95
75
45
30
20
15
10
Temperature Q Value for my unknown
water sample:
____________________________
5. Determining Q value for Conductivity (Total dissolved solids)
Total Dissolved Solids
0
50
100
150
200
250
300
350
400
450
500
Q Value
80
90
85
78
72
65
60
52
46
40
30
Conductivity Q Value for my unknown
water sample:
____________________________
3
Name:
Total of Q values
Record the calculated Q values for each test in the table below under column A. Multiply these
values by their weight (Column B) – this will give you the “Total Q-Value” in column C.
Add the total-Q values together to get the Overall quality value. The closer your value is to 100,
the better the quality of water.
Note: This quality calculation is not a complete one – it only includes 4 measurements. More
complete quality testing includes fecal coliform counts, biological oxygen demand, phosphate
and nitrate levels, turbidity, as well as a count of the macroinvertebrates in the water.
Test
Dissolved Oxygen
pH
Conductivity
Temperature
Q-Value
Weight
0.38
0.24
0.16
0.22
Total Q-Value
Overall Quality: ______________________
Questions
1. Based on the above data, which of the 6 locations do you think your water sample came
from? Justify your answer using the data.
2. Based on the data provided, what changes may need to be made to the rainbow trout tank,
if any? If no changes need to be made, suggest how the acceptable Q-values of their
environment may be harder to maintain as the trout increase in size.
4