High fixed residue at 180°

The  fixed residue at 180 °mg/l is the residue of mineral salts of a water brought to boiling point up to 180°.

This value is used in mineral water to indicate the total weight of mineral salts.

The lower the value, the lighter the mineral water is.

A high value of the Residue fixed at 180° indicates that the water contains mineral salts with a significant weight.