DKH
Degrees of carbonate hardness is a unit of water hardness, specifically for temporary or carbonate hardness. Carbonate hardness is a measure of the concentration of carbonates such as calcium carbonate and magnesium carbonate per volume of water. Specifically, 1 dKH is defined as 17.86 milligrams of calcium carbonate per litre of water, i.e. 17.86 ppm. Since a mole of calcium carbonate weighs 100.09 grams, 1 dKH is equivalent to 0.17832 mmol per litre.
dKH are the same as °fH, degrees of French hardness.
