Tropic Marin KH Alkalinity Test Kit
For the precise determination of alkalinity (carbonate hardness)
Alkalinity characterises the buffer capacity, i.e. the ability to maintain the pH value of water. It is determined by the proportion of bicarbonate ions in the water and is, therefore, also known as carbonate hardness. With increasing pH, other basic ions such as hydroxide ions, also contribute to the alkalinity. If the proportion of bicarbonate ions is too low, this can cause a strong drop in the pH value (drop in acidity), which can threaten the lives of many fish and invertebrates. In sea water, carbonate hardness also plays an important role in the construction of the calcarous skeletons of hard corals. A high degree of carbonate hardness can lead to lime precipitation in sea water and negatively affect the growth of corals.
For freshwater aquariums, the carbonate hardness should not drop below 3 °dH (degree of German hardness); the optimum alkalinity depends on the fish population. The Tropic Marin® KH-/ALKALINITY-TEST PROFESSIONAL allows the buffering capacity of the water in your aquarium to be checked promptly and precisely with an accuracy of 0.1 °dH.
• For determining the alkalinity with an accuracy of 0.1 °dH • Determine the buffer capacity of the water and ensure the stability of the pH value • This test kit will do approximately 50 tests (depending on test results) that are both fast and accurate • Simple determination by clearly distinguishable colour changes •
Measurement in °dH (Conversion Table for other units in the instruction manual included)
How to use:
1. Shake the dropper bottle reagent A well before use!
2. Rinse the cuvette several times with aquarium water and, using the large dosing syringe, fill with 5 ml of the water sample.
3. Then add 3 drops of reagent A (indicator) and carefully shake the cuvette. The water sample turns turquoise blue.
4. Fit the enclosed dropper tip on the small dosing syringe and draw the plunger up to the 1 ml mark with reagent B (titrator). The bottom end of the plunger is now at the 1 ml mark. The air bubble under it does not affect the test result.
5. Slowly add reagent B from the syringe to the water sample until this changes its colour from turquoise through dark blue and violet to a clear pink with no tinge of blue.
At the start, part of the reagent B can be carefully added, up to nearly the expected transition point. Then shake the sample and continue, by adding reagent B dropwise. Carefully shake the cuvette after each drop. The measurement is finished when the colouring of the sample reaches a clear pink tone with no tinge of blue (see colour fields on the packaging).
6. The consumption of reagent B multiplied by 10 gives the carbonate hardness in °dH.
For example: if the lower end of the syringe plunger is at 0.28 ml after the end of the titration, the consumption of reagent B is 0.72 ml (difference to 1 ml). 0.72 x 10 = 7.2. The carbonate hardness of the aquarium water is 7.2 °dH.
To enhance the number of measurements with this testkit or for hard water above 10 °dH, the test can be carried out with 2.5 ml sample. In doing so, proceed as described above and multiply the consumption of reagent B by 20 after the end of the titration.
How to correct unfavourable values?
To increase alkalinity / carbonate hardness, we recommend Tropic Marin® RE-MINERAL TROPIC for freshwater use.
If the carbonate hardness is too high and needs to be reduced, we recommend changing the water in fresh water. Contact your local supplier for more information.
We recommend using the reagents within 12 months from when they are opened.
The entire instruction manual as PDF file can be found here: KH-/ALKALINITY-TEST PROFESSIONAL