Improper Hardness

IMPROPER HARDNESS

  • Hardness is a measure of the divalent metal cation (e.g., calcium, iron, zinc, magnesium) concentration in water. In most waters, it is composed almost entirely of Ca++ and Mg++.
  • Total hardness values (in mg/l as CaCO3) usually will be similar to alkalinity values (in mg/l as CaCO3) because the alkalinity of most natural waters comes primarily from carbonate salts of calcium and magnesium. Other divalent or trivalent metal ions are relatively uncommon in natural waters.

Diagnosis of improper hardness

  • Hardness is usually expressed as mg/l equivalents of calcium carbonate. In marine or brackishwater pond systems, calcium levels increase with increasing salinity, thus, if the salinity is optimal for growth, calcium levels usually will be satisfactory. However, hardness can significantly decrease in marine aquaria that contain corals, crustaceans, or other invertebrates that use large amount of calcium during growth.

Treatment of improper hardness

  • If hardness is too low - Add calcium
  • If hardness is too high (aquaria)
    • Do water change with deionized water or other low hardness water
    • Filter water through peat.
Last modified: Friday, 16 September 2011, 11:53 AM