The pH Buffer Capsule Kit (
To prepare the proper solution to use as the storage solution for our pH Sensors, add the contents of one orange (pH 4) powder capsule, 3 drops of preservative, and 10 grams of solid potassium chloride (KCl) to 100 mL of distilled water. Stir the mixture thoroughly.
Note that the preservative also contains a universal indicator, thus your mixture will not be clear. This color will not harm your sensor.
We also sell storage solution as pH Storage Solution (