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USER INSTRUCTIONS AQUA TEST
GB
NH
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GENERAL
With the help of the Velda NH
Test the ammonium / ammonia content of fresh and salt water can
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be determined quickly and quite accurately. Both for garden ponds and for aquaria it is important to
have an insight into the ammonium / ammonia content of the water. Nitrogen compounds can be
present in water in many forms. It can be distinguished between organic and inorganic nitrogen
compounds. The organic compounds consist for the major part of proteins and amino acids. The
proteins are the basic material for the inorganic compounds, namely ammonium (NH
), nitrite
4
(NO
) and nitrate (NO
). The conversion of proteins into the ultimate nitrate is referred to as the
2
3
nitrification process. It occurs with the help of the nitrosomas and nitrobacter bacteria and is strictly
aerobic. This means that the process only starts under oxygen rich conditions. If inorganic ni-
trogen compounds are present in the water environment in high concentrations, this suggests
seriously water pollution, which may result in death of fish.
The ammonium and ammonia compounds are in a certain ratio to each other. This ratio is con-
trolled by the pH level. At a low pH level the ammonium part is much larger than that of ammonia,
whereas at a high pH level, the ammonia part will become larger. A correct determination of the
ammonium and ammonia content consequently is only possible if the pH level is known. For pond
fish ammonium is a relatively harmless compound. Ammonia, however, at a concentration of
0.2 mg/l, is already fatal for spawn and at 0.8 mg/l it is for all fish.
INSTRUCTIONS FOR USE
Rinse the graduated beakers well and fill them with 5 ml of water to be tested. To one graduated
beaker add while shaking slightly 1 drop of NH
test liquid no. 1, followed by 5 drops of NH
test
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liquid no. 2, subsequently 1 drop of NH
test liquid no. 3 and finally 5 drops of NH
test liquid no. 4.
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At each addition swirl slightly. Now close the graduated beaker with the cap and shake well. Take
the cap off the graduated beaker. Shift the colour chart in the comparator and place the graduated
beakers in the holes that are destined for them. Place the beaker containing the test liquid in the in-
nermost opening of the comparator. Wait for 4 minutes. Now turn the colour chart until both beakers
are showing the same colour when looking from above. The similar colour indicates the ammonium/
ammonia content in mg/l. Determine the colour by daylight, however, not right in the sun. After use
rinse the graduated beakers well. Determine the pH value, with the help of the Velda pH test
G
(not supplied along). As soon as this value is known, the ammonia content can be read with the
help of the table (at the end of this manual). This test practically has an unlimited shelf life, provided
that it is kept cool and dark. Keep away form children.
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