Please interfere 1 measuring cup (~ 7 g) of Calcium hydroxide in 10 l demineralized water and let depose in an hermetically locked container over night.
With the clear liquid the aquarium water evaporated can be filled up drop by drop.
Do not admit at on time, since thereby the pH-value could rise strongly.Warning :
Causes causticization !
In case of contact with the eyes, please flush
carefully with water and see a doctor.
Please keep away from children