NTLABS GH B Reagent

General Hardness is a measure of the total amount of minerals dissolved in the water. Water hardness lies on a spectrum between ‘soft water’ or ‘hard water’ depending on the amount of dissolved minerals: the more minerals present, the greater the hardness. Hard water is responsible for the build-up of limescale.

This test kit measures GH in dGH (where one degree = 17.8 ppm as CaCO3). For pond fish, between 8 and 12 dGH is ideal.