JBL TestLab Handbuch Seite 48

colour. Let set for 1 minute and then shake gently once more.
5. Place the tube for reading the potassium content on the cross of the color card.
6. The following procedure should be carried out in light, diffuse light. The turbid water is filled in as long as the
tube for reading until the cross on the color card through the haze from above is no longer visible from the
measuring tube.
7. The potassium content can now be read on the scale of the measuring tube (bottom of the meniscus).
Instructions for the Potassium Test in salt water:
1. Dilute the aquarium water you wish to test 1:30 with potassium-free water or distilled water (e.g. JBL Dest),
e.g. fill 10 ml to 300 ml.
2. The other steps correspond to the instructions for fresh water.
3. Multiply the test result by a factor of 30.
Our tip for ecologically minded users:
All reagents for the JBL Test Sets are commercially available as reasonably priced refills!
Storage:
Store in a cool (+5 °C to +25 °C ) and dry place.
Warning and safety notices reagent 1:
Danger
Causes severe skin burns and eye damage. If medical advice is needed, have product
container or label at hand. Keep out of reach of children. Wear protective gloves/protective
clothing/eye protection/face protection. IF IN EYES: Rinse cautiously with water for
several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
Immediately call a POISON CENTER or doctor/physician.
Warning and safety notices reagent 2:
Attention
Causes serious eye irritation. If medical advice is needed, have product container or label
at hand. Keep out of reach of children. Wear protective gloves/protective clothing/eye
protection/face protection. IF IN EYES: Rinse cautiously with water for several minutes.
Remove contact lenses, if present and easy to do. Continue rinsing.
Mg Magnesium Test Set for fresh water
Special features:
The JBL Mg Magnesium Test Set (fresh water) is designed for measuring and doing routine checks of
magnesium content in freshwater aquariums within a range of 0 - 10 mg/l (ppm).
Why test?
Magnesium and calcium together form the total hardness. Like potassium, magnesium is a macroelement which
is required for healthy and strong plant growth. The magnesium levels in mains water (including water with a high
total hardness) are very often too low for aquatic plants, so that deficiency symptoms appear after a short time
already. The symptoms of magnesium deficiency are similar to those of iron deficiency. Yellowing (chlorosis)
occurs between the veins of the leaves. This may be significantly more pronounced than in iron deficiency.
Incurved leaves are another symptom. These symptoms are not just limited to old leaves and instead, also appear
in new fresh leaves. As a result, the available magnesium concentrations may be too low, causing plant growth to
stagnate, even if the aquarium water is fertilised regularly (e.g. weekly). We recommend daily measurements of
the potassium concentration of your tank water initially. This permits determination of the plants' requirements and
corresponding correct dosing of the fertiliser. Afterwards, you can gradually change over to routine measurements
carried out at longer intervals. The value should be somewhere between 5 and 50 mg/l for good plant growth.
Remedial measures for fresh water:
Magnesium concentration too low (< 5 mg/l): Fertilisation with JBL Ferropol or JBL ProScape Fe +Microelements
and with JBL ProScape Mg Macroelements in particular.
46
UK