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Test Instructions - 1 step only


Each kit will give you 200 tests.

  1. Using the 5 ml syringe add 5ml of aquarium water to the test vial.
    Attention: before any use of the vial test, make sure it is washed with RO water only and dry it up with a soft paper.
  2. Using the 1 ml syringe, place the metal needle firmly and draw up the Alk-2 until the lower end of syringe's black rubber is right on the 1.00 ml mark.
    • Before this step, ensure that the needle is empty of liquids and that it's submersed in water the entire time to avoid air entering to the syringe.
    • The presence of a layer of air between the liquid and the black part of syringe is normal and will not affect the result (The normal air layer you should see is equal to 0.1 ml).
  3. Start adding Alk-2 to the test vial one drop at a time, swirling a little after each drop. 3. 
    After 2-3 drops you will get solution with blue color       
  4. Continue adding Alk-2 to the test vial until the color will change to yellow       
    • There will be short stage of green color. The final result is when the solution is changed from green color to yellow. When the solution is green you are very close to the final result - about (1-2 drops).
    Pay attention that by adding Alk-2 more than needed the yellow color will get brighter.
  5. 5. Note the position of the lower black part of syringe (each division corresponds to 0.01 ml) and obtain the alkalinity result from the table. Readings should be taken at the position of the lower end of syringe's black rubber.

    NSW alkalinity is around 7. Our recommendation is to keep DKH levels in the tank between: 7-10.

    In case of low alkalinity use Royal Sodium Bicarbonate powder or liquid to keep parameters between: 7-10.


  • Alkalinity can be measured by titration a sample with a strong acid until all the buffering capacity of the aforementioned ions above, the pH of bicarbonate or carbonate is consumed. This point is functionally set to pH 4.5.

    At this point, all the bases of interest have been reached to the zero level; hence they no longer cause alkalinity.

    Alkalinity is typically reported as CaCO3.
    This can be converted into equivalents (dKH) when one equivalent is equal to 17.848mg/L.

    Each test uses a two-part chemical reaction and a syringe. Unlike the Ca and Mg test, here we add the chemical solution to the sea water until the final color is hit. We also guarantee you’ll get 200 tests out of each dKH test.

    In Royal Nature Alkalinity test the correlation between end point of titration and value of alkalinity was calculated with a lot of adjustments. Our ability to produce in small batches is crucial to achieve analytical calibration which is a key to our test’s accuracy.

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