To keep an eye on the quality of the water in my aquarium
I regularly do some water test for a number of water values. On this page I will
describe which tests I use in my aquarium en wherefore I use
them followed by a description of the brands of the tests.
At the bottom of this page I will also show a number of test
results from my own aquarium.
The tests I use
I use a number of water test in my aquarium to check the quality
of the water in my aquarium. Below I will describe these tests, divided in three
categories. The three categories are test for the benefit of the fishes, test
for the benefit of the plants and test to prevent algae growth.
Tests for the benefit of the fishes The check if the water values in my aquarium are right for my
fishes I use three different tests. These test are tests to measure the acidity
(pH), the sum of earth alkalines (GH) and the nitrite level (NO2).
The right acidity and GH are just as important for the health of many fishes as
the temperature of the water. Through the pH and the GH test I can check if the
water values of my aquarium are right for the fishes I have in it. Especially
the pH in an aquarium can change easily through a large number of processes and
is therefore a value that must be checked regularly.
The nitrite
test is especially important for a newly set up aquarium. Especially in a newly
set up aquarium there can be high nitrite levels which can be lethal for the
fishes in the aquarium. With a newly set up aquarium it's very important to test
the nitrite level to prevent fishes from dying. When an aquarium is running for
a longer time this test isn't very important anymore because nitrite problems seldom
happen when an aquarium is running well.
Tests for the benefit
of the plants I personally are a fan of an aquarium with a large number of
plants in it. To get optimal conditions for my plants I use a CO2
system and plant fertilization,
but these products also bring risks with them for the fishes and can possibly
lead to rapid algae growth. To minimize these risks I use a number of water
test. To check my CO2 system I use a pH (acidity) test and
a KH (carbonate hardness) test. With the results of these test and the table
below I can check the CO2 level in my aquarium. For this purpose
I also used a CO2 test from the brand Tetra
for a while, but this test was inaccurate and therefore I now use the method
with the table below.
Tabel: optimal CO2
level
To many CO2
Optimal
To less CO2
Increase hardness of the water
KH\pH
6.0
6.2
6.4
6.6
6.8
7.0
7.2
7.4
7.6
7.8
8.0
0.5
15
9.3
5.9
3.7
2.4
1.5
0.93
0.59
0.37
0.24
0.15
1.0
30
18.6
11.8
7.4
4.7
3.0
1.86
1.18
0.74
0.47
0.30
1.5
44
28
17.6
11.1
7.0
4.4
2.8
1.76
1.11
0.70
0.44
2.0
59
37
24
14.8
9.4
5.9
3.7
2.4
1.48
0.94
0.59
2.5
73
46
30
18.5
11.8
7.3
4.6
3.0
1.85
1.18
0.73
3.0
87
56
35
22
14
8.7
5.6
3.5
2.2
1.4
0.87
3.5
103
65
41
26
16.4
10.3
6.5
4.1
2.6
1.64
1.03
Optimal hardness
4.0
118
75
47
30
18.7
11.8
7.5
4.7
3.0
1.87
1.18
5.0
147
93
59
37
23
14.7
9.3
5.9
3.7
2.3
1.47
6.0
177
112
71
45
28
17.7
11.2
7.1
4.5
2.8
1.77
8.0
240
149
94
59
37
24
14.9
9.4
5.9
3.7
2.4
Decrease hardness oft the water
10
300
186
118
74
47
30
18.6
11.8
7.4
4.7
3.0
15
440
280
176
111
70
44
28
17.6
11.1
7.0
4.4
20
590
370
240
148
94
59
37
24
14.8
9.4
5.9
CO2-level in
mg/l, carbonate hardness in ºdKH
To use the right amount of fertilizer for my plants I use an
iron (Fe) test. Because one of the main ingredients of aquarium plants
fertilizer is iron, an iron test can be used to check if you use the right
amount of plants fertilizer. This because the advised quantity of plants
fertilizer by manufactures is in my opinion
much to high and also I don't think that every aquarium has the same needs for fertilization.
Therefore if you use fertilization for your plants you always need an iron test
to check if you don't use to much. Otherwise you take the risk of getting an
algae plague.
Tests to prevent algae growth Algae growth in the aquarium is often caused by high levels of
phosphate
(PO4) and nitrate (NO3). Although
the height of these water values aren't very important for the fishes the
phosphate and nitrate level can be an indication of possible problems with
algae. I personally are curious about the relation between the phosphate and
nitrate level in the aquarium and algae growth and therefore I do also use a
nitrate test and phosphate test to check my aquarium water.
The brands I use
For the measuring the following water values I use the tests of the brand Dupla: degree of acidity (pH), carbonate hardness (KH), sum of
earth alkalines (GH), nitrite
level
(NO2), the iron level (Fe) and the phosphate level (PO4).
Only for the nitrate level (NO3) I use a test of another
brand, namely of Tetra. For a
while I used the nitrate test of but this test went bad pretty soon a couple of
times and also one time is already wasn't good anymore when I bought it. Maybe
this test was already to old, but this can't be checked because there is no
fabrication data printed on the test. Therefore I switched to the nitrate test
of Tetra, this test is less accurate but is also less expensive than the test of
Dupla. With this nitrate test of the brand Tetra was also a nitrite test but
this so inaccurate (gives a reading from 1 mg/l) that the fishes are almost dead
before you measure some nitrite. Also it's wise to keep the test in a cold place so they don't go bad to
soon.
Water values of my aquarium
Below the last three measurements of my aquarium water are printed in a
table.
e
level
(NO2), the iron level (Fe) and the phosphate level (PO4).
Only for the nitrate level (NO3) I use a test of another
brand, namely of Tetra. For a
while I used the nitrate test of but this test went bad pretty soon a couple of
times and also one time is already wasn't good anymore when I bought it. Maybe
this test was already to old, but this can't be checked because there is no
fabrication data printed on the test. Therefore I switched to the nitrate test
of Tetra, this test is less accurate but is also less expensive than the test of
Dupla. With this nitrate test of the brand Tetra was also a nitrite test but
this so inaccurate (gives a reading from 1 mg/l) that the fishes are almost dead
before you measure some nitrite. Also it's wise to keep the test in a cold place so they don't go bad to
soon.