Velda Aqua Test Mode D'emploi page 20

USER INSTRUCTIONS AQUA TEST
GB GH
GENERAL
With the help of the Velda GH Test the total hardness, also referred to as calcium and magnesium
value, of fresh water can be determined quickly and quite accurately. The JH value is expressed in
German degrees of hardness, for example JH 8 °GH. Both for garden ponds and for aquaria it is
important to have an insight into the total hardness of the water.
JH VALUE OF PONDS
Soft pond water can acidify easily. Continuous rainfall will intensify this process. Especial-
ly in autumn and winter this can result in death of fish. Also the growth of oxygen producing
plants will be inhibited at a too low JH value. Regular inspection (4 to 5 times a year) of the
JH value is therefore desirable. A healthy and stable pond environment has a total hardness
of JH 8 up to 12 °GH. If the value will decrease below JH 7 °GH, measures have to be taken
With the help of Velda GH Plus the total hardness can be increased without any problem.
Never add GH Plus and KH Plus at the same time, but with an interval of a few days.
JH VALUE OF AQUARIA
For a company aquarium the JH value may vary from JH 8 to 12 °GH. Most fish and plants
can develop well then. For special aquaria there may be exceptions. Aquarium literature
gives decisive answers on the subject.
INSTRUCTIONS FOR USE
Rinse the graduated beakers well and fill them with 5 ml of water to be tested. Shift the neutral
chart in the comparator and place the graduated beakers in the holes that are destined for them.
Add, while shaking slightly, to one of the graduated beakers so many drops of GH test liquid till the
initial colour red will turn blue. The change in colour can be seen most clearly from above. The
number of drops added will determine the JH value (1 drop = 1 °GH). To be sure that the
measurement is correct, you may repeat this test, if necessary, with another graduated beaker.
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After use rinse the graduated beakers well.
You should bear in mind that in very soft water the change in colour is hard to see. If no change in
colour occurs, the value is less than JH 2 °GH. Keep away form children.
MEDICINE AND PESTICIDES
When administering fish medicine, algae and snail killers it is necessary to determine the JH value
of the water, before passing on to treatment. At a JH value below 5 °GH the buffering power of the
water is low. In that case the action of medicine and pesticides is far more intensive, as a result of
which the dosage indicated can easily harm fish and plants. At a JH value less than 5 °GH it is
therefore advisable to halve the dosage of medicine and pesticides.