Category Archives: Aquarium

Fish keeping, shrimp keeping, keeping anything lives under water :) Freshwater only at the moment.

General Hardness (GH) – Ca:Mg Conversion

This short article to remind me that 1 dGH (1 German degree of water general hardness) is 7.2 ppm Ca++ or 4.3 ppm Mg++, also provided Ca:Mg conversion/ratio calculator.

GH – General Hardness AKA: Permanent Hardness

GH is the measure of Calcium and Magnesium salts (to a small extent, other divalent cations). These are cations with a 2+ charge.  All fresh water sources contain calcium and magnesium in varying quantities. They form salts with anions (which have a negative charge). The most important of these are bicarbonate HCO3 and sulphate SO42-. Continue reading General Hardness (GH) – Ca:Mg Conversion