Velda Aqua Test Mode D'emploi page 23

USER INSTRUCTIONS AQUA TEST
GB NO
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GENERAL
With the help of the Velda NO Test the nitrite content of fresh and salt water can be determined
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quickly and quite accurately. Both for garden ponds and for aquaria it is important to have an
insight into the nitrite content of the water. Although nitrite is almost always present in water, it will
not be detectable in duly flourishing garden ponds and aquaria. In a biologically functioning water
environment it will at once be decomposed into nitrate by nitrifying bacteria. This last phase in the
process (nitrate) will be absorbed by plants and / or algae. A too high nitrite content may occur
when the bacterial decomposition process is upset. In that case there is an insufficient number of
nitrifying bacteria to take care that the dangerous nitrite will be decomposed into the harmless
nitrate. Especially in newly sunk ponds and aquaria interferences in the nitrification process may
easily occur, as a result of which a too high nitrite content will form (over 0.2 mg/l).
In certain cases nitrite accumulation can be the result of a too high
nitrate level. The decrease in nitrate stagnates owing to the presence
of growing plants and / or algae. Owing to this, nitrite can no longer be
converted into nitrate, which results in a too high nitrite content (over
0.2 mg/l). In this case it is necessary to refresh the water and add more
growing plants.
If nitrite is found it is advisable to apply Bacterial. Bacterial is a product
of Velda which contains billions of nitrifying bacteria. These bacteria
make sure that the nitrite content will be quickly reduced below 0.2 mg/l.
If a nitrite content from 1 mg/l is found, part of the water should be re-
freshed immediately. Consequently Bacterial can be added.
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 5 drops of NO test liquid no. 1, followed by 5 drops of NO no. 2.
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Now close the graduated beaker with the cap and shake well. Take the cap off the graduated bea-
ker. 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 innermost opening of the com-
parator. Now turn the colour chart until both beakers are showing the same colour when looking
from above. The similar colour indicates the nitrite content in mg/l. After use rinse the graduated
beakers well.
The speed at which any discolouration will develop, depends on temperature. Wait for at least 5
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minutes with the judgement of water having a temperature below 20 °C. This test practically has
an unlimited shelf life, provided that it is kept cool and dark. Keep away form children.