The Salifert KH/Alk test is very straightforward. It measures in sufficient small steps of 0.1 meq/L or 0.3 dKH with a sharp color change. This makes detection of important yet small change possible.
The kit can perform approx. 100 – 200 measurements.
Add with the 5 ml syringe 4 ml of water in the test vial. For a lower resolution and more tests per kit add 2 instead of 4 ml.
Shake the KH-Ind dropping bottle a few times and add 2 drops in the test vial (1 drop for the low resolution mode).
Put the plastic tip firmly on the 1 ml syringe. And draw into the syringe the KH reagent (ensure that the end of the plastic tip is constantly submersed in the KH reagent) till the lower end of the black part of the piston is exactly at the 1.00 ml mark. There will be some air present just below the piston. This is the air which was present between the end of the plastic tip and the piston. This will not influence the test result.
Add dropwise with the 1 ml syringe the KH reagent to the water in the test tube. Swirl after each drop a second or two. Continue with this until the color changes from blue/green to orange-red or pink color (whichever color is observed first).
Hold the syringe with the tip facing upward and read the position of the, now the upper end, of the black part of the piston. The syringe has graduations of 0.01 ml. Read the KH or alkalinity value from the table or calculate as follows.KH in dKH = (1 – reading in step 5) x 16Alk in meq/L = (1 – reading in step 5) x 5.71If you have chosen for the lower resolution multiply the calculated result by 2.Natural sea water has a KH of 8 dKH or alkalinity of 2.9 meq/LKH and alkalinity are increased safely with Salifert`sKH + pH Buffer.