Experiments with water (experiment 1-4)

Sindelfingen

We used the Fishwater Lab.
We worked with the usual reagents in this Lab, but we don’t know how they are called.

Ammonium (NH4+):

We tested the concentration of ammonium in the different samples of water in our following experiment:

Test description:
The samples of water are mixed with two reagents. Altogether the time of reaction takes 12 minutes.

Result:
Concentration of ammonium:
Sample of water 1: <= 0.05 mg/l
Sample of water 2: <= 0.05 mg/l
Sample of water 3: <= 0.05 mg/l

Interpretation:
The samples of water are not toxic, if we take the directives of “Drinking Water Ordinance“ as basis of our interpretation. They are also qualified for being fish water and bathwater.

Translation from Sabrina, content from Sylvia and Sabrina

Ammonium has an important function, because it produces a balance to ammoniac. Ammonium isn’t toxic for fish in contrast to ammoniac, which is extremely toxic. 1 mg/l ammoniac leads very fast to asphyxiation of the fish because the ammoniac attacks the gills.
Therefore 0.2 mg/l for sensible and 0.5 mg/l for less sensible fish should not be exceeded.
This balance between these two substances depends significantly on the pH-value and the temperature of the water. The higher the temperature is the higher the content of ammoniac becomes. When more ammonium is available the solution is acid and when the content of ammoniac is higher the solution becomes alkaline. When the water is acid because of a too high content of ammonium the oxygen will be consumed. The bacteria cause increased oxidations and therefore they consume the oxygen. On the other hand a surplus of ammonium takes a positive effect of the content of oxygen in the water because it stimulates the growth of the micro algae. The micro algae do photosynthesis and produce oxygen. During the day it may come to a super saturation of oxygen because of the increased number of micro algae. In the night however the content of oxygen decreases extremely because the micro algae don’t do photosynthesis and the plankton breathes. The plankton has increased significantly because of the surplus of ammonium. During the night the content of oxygen can decrease now extremely also under the necessary values. This will cause to an overbalance of the water, which means there are areas without oxygen resulting in fish kill.

Sabrina (translation + content)

Hardness of carbonate (CO3):

Test description:
You will need only one reagent.

Result:
Sample of water 1: 9 drops, level 2 soft/medium
Sample of water 2: 4 drops
Sample of water 3: 7 drops

Translation from Sabrina, content from Sylvia and Sabrina

Summary:

Carbonate hardness and acid connection ability:

It ranks among the temporary hardness, which by hydrogen carbonates,
carbonates by magnesium and calcium, which are present solved, one causes.
By cooking water with carbonate hardness, this can be extracted.

The acid connecting ability (SBV), describes a number on
ml 0,1 mol/l from hydrochloric acid.

Assistance of the carbonate hardness and the acid connection ability can
one the fertility of a waters determine, (fruitfully lime-rich water means):

SBV in mol/l
Type of waters
0 – 0.5
arm
0.5 – 1.5
Moderate fruitfully
over 1.5
fruitful

Sylvia (translation + content)

Iron (Fe):

Test description:
You will need only one reagent.

Result:
Sample of water 1: < 0.05 mg/l
Sample of water 2: < 0.05 mg/l
Sample of water 3: < 0.05 mg/l

Summary:
The samples of water do not pass over the limits of the measurement range for fish water and Drinking Water Ordinance.

Translation from Sabrina, content from Sylvia and Sabrina

Iron:
Iron is an essential micro element for water organisms. Fish, macrophyt (big algae) and micro algae need iron for their metabolism (e.g. to build haemoglobin). Under special conditions iron can precipitate (from Fe 2+ to Fe 3+) and it builds in the bed of the water the so-called ‘Ausockerung’. In this case young fish suffer damages although it is vital, to much iron can function toxic. Therefore the limit of iron in fish water is next to 0.1 – 0.2 mg/l. In our samples of water the content of iron is in a normal range and therefore very suitable for the growth of young fish.

Sabrina (translation + content)

Total hardness (Ca, Mg):

Test description:
You will need only one reagent. To get a result we need to count the drops.

Result:
Sample of water 1: soft/medium water (8 drops)
Sample of water 2: soft /medium water (10 drops)
Sample of water 3: very soft water (6 drops)

Summary:
Classification of the hardness of the water:
0-4°d – very soft water
4-8°d – soft water
8-18°d – medium water
18-30°d – hard water
over 30°d – very hard water

Translation from Sabrina, content from Sylvia and Sabrina

The Total hardness of the water:

Among the total hardness one ranks the sum of all existing solved concentrations in the water, e.g. like Calcium and magnesium carbonate or also salts.

There are two different types of groups in addition belong the total hardness of water:
Type 1. The temporary hardness is converted (Hdrocarbonate),
which with heating up into carbon dioxide and insoluble carbonates.
Type 2. The permanent hardness of the water,
which remain with heating up further a solution.

If you want to describe the total hardness of the water you can use the following units:
Degree of the German hardness (°dH):
1 °d corresponds to the quantity of the ions per litre which in 10 mg Ca 3(Co) is contained.
In addition there is the English hardness (°e), the French hardness (°f)
and the American hardness (°US), which are converted as follows:
1° dH = 1.25° e = 1.78° f = 17.8° US = 17.8 mg/l Ca 3(Co)

The water hardness is divided into the following ranges:

softly („1”, < 7 °d),
centralhard („2”, 7 bis 14 °d),
hard („3”, 14 bis 21 °d)
very hard („4”, > 21 °d)

Sylvia (translation + content)