JBL TestLab Handbuch Seite 30

KH Test Set
Features
The JBL KH Test Set is an easy to use quick-test for determining the carbonate hardness or the acid binding
capacity of freshwater, saltwater and garden pond water.
Why test?
Depending on origin and consistency of the subsoil, water may contain varying quantities of alkaline earth
salts. Owing to the effects of CO
definition, the proportion of calcium and magnesium salts represented as carbonate is described as carbonate
hardness. As a rule, the carbonate hardness is below the total hardness value. In certain exceptional cases
(e.g. the East African lakes) the carbonate hardness can be higher than the total hardness.
Most freshwater fish and plants in an aquarium thrive well at a carbonate hardness of roughly between 3 and
15°d. For successful CO
buffering action in saltwater, a carbonate hardness around 7-10°d ought to be maintained.
In the garden pond the carbonate hardness plays a vital role as a stabilizer for the pH level. Algae (thread
and floating algae) in particular "consume" carbonate hardness by rapid assimilation (biogenic decalcification),
driving the pH up to levels which are dangerous for fish (above 10° d). Carbonate hardness levels of at least 4°
d should therefore be maintained in garden ponds.
What to do in the event of unfavourable values
There are various methods for reducing water hardness (e.g. by using a reverse osmosis unit such as the JBL
Osmose 120). Ask your pet shop specialist for details. Use JBL AquaDur Plus or JBL pH-Plus to increase the
carbonate hardness in freshwater aquariums. Use JBL CalciuMarin in marine aquariums.
In garden ponds the carbonate hardness can be increased by the addition of JBL StabiloPond KH.
Instructions
1. Repeatedly rinse the measuring vessel with the water to be tested.
2. Fill the measuring vessel with the water to be tested up to the 5 ml mark (CAUTION: the lower line of the water
level must coincide with the marking).
3. Add reagent one drop at a time, counting the drops, and shake after each drop until the colour changes from
blue to yellow-orange.
4. One drop of reagent solution used corresponds to 1° carbonate hardness (German scale).
For more precise readings:
Fill the measuring vessel up to the 10 ml mark with the water to be tested.
One drop of reagent solution used up corresponds to 0.5° general hardness (German scale).
Note: With 10 ml sample water the colour development is less intensive for the first drops. For better readability
place the measuring vessel on a white surface.
See the table below for conversion into other common units of measurement.
Carbonate hardness
Acid binding capacity mmol/l
German degree °d
French degree °f
Hydrogen carbonate mg/l
Our tip for environmentally-friendly users
All reagents for JBL test sets are available from your retailer as reasonably-priced refill packs!
, a large proportion of these salts is represented by hydrogen carbonates. By
2
fertilization, the carbonate hardness should not fall below 4 to 5°d. For optimized pH
2
Acid binding capacity
mmol/l
-
0.36
0.20
0.016
German
degree °d
2.78
-
0.56
0.046
28
French Hydrogen
degree °f carbonate mg/l
4.94 61.0
1.78 21.8
- 12.3
0.08
UK
-