Measures overall and carbonate hardness reliably and precisely
-for all freshwater aquariums
-for a large number of analyses
-excellent long-term stability
The Tetratest GH is suitable for testing water from freshwater aquariums and garden ponds. Do not use for marine aquariums as the general hardness in seawater reaches levels above 300º dH.The Tetratest KH is suitable for testing water from freshwater aquariums and garden ponds as well as from marine aquariums.
Tap water and thus aquarium water demonstrate a variety of chemical characteristics depending largely on the water source.Two of the most important values of water quality are the general and carbonate hardness. The Tetratest kits measure both of these values in German degrees of hardness dH.
The general hardness (GH) of the water is a measure of the dissolved calcium and magnesium salts.These salts directly influence the metabolism of fish, plants and microorganisms.Water with a high calcium and magnesium salt content is referred to as hard and with a low content as soft.Most freshwater fish thrive at a general hardness level between 6° ? 16° dH.
The carbonate hardness (KH) of the water is determined by the carbonate and bicarbonate content. Thism measurement is particularly important as the KH and pH values are interdependent. The KH value is a measurement of the buffering capacity of the water.A sufficient carbonate hardness level will prevent a dangerous decrease of the pH level and an excessive acidification of the water. A KH value of 3°-10° dH is recommended for most freshwater fish.Seawater fish require higher values between 8°-10° dH.
Please read this section completely before starting the test.
1. Rinse the test vial with the water to be tested
2. Fill the test vial to the 5 ml (cc.) mark with the water to be tested
3. Hold the liquid reagent bottle upside down and add a drop at a time to the test vial.
4. Gently shake the vial after each drop and count the number of drops necessary to cause a color change.
5. GH: Color change from red to green. KH: Color change from blue to yellow
Note: if the color change occurs right after the first drop, the level is between 0 and 1º dH
6. The number of drops added until the color changes represents the level of hardness (German hardness).
For instance, 3 drops = 3º dH.
After each test, rinse vial thoroughly with tap water
Note: The measuring accuracy increases if the test is performed with 10 ml of aquarium water
(1 drop testing fluid = 1/2º dH).