what do siamese fighting fish eatPLEASE follow the little guys pH parameters, which I describe in each Tetra description for your comfort. What is dGH?Degrees of usual hardness dGH are units of water hardness, especially to common hardness. General hardness is a measurement for the number of calcium and magnesium cations per volume of water. A cation is a definitely charged ion that has fewer electrons than protons. 1dGH corresponds to 10 mg of calcium oxide or magnesium oxide per liter of water. In water testing, the paper strips degree hardness in parts per million ppm one part per million is one milligram mg of calcium per liter of water.