What does KH in the aquarium mean in practice?
KH is a practical measure of the bicarbonate buffer that stabilizes pH and is consumed by biological processes and CO2 dosing.
When does it matter?
Very low KH increases the risk of a sudden drop in pH, but the required level depends on the biotope and the method of maintaining the tank.
Which solutions are related to it?
It is measured separately from GH and corrected gradually with bicarbonate salts or appropriate remineralization.