General hardness (GH) indicates the quantities of magnesium and calcium salts dissolved in water. The recommended level is between 6 and 20°GH in freshwater, depending on the species kept. Use this Aquarium Systems SeaTest to make sure your fish can thrive in the best possible conditions for their species.
- For freshwater only.
- 1 drop = 1°GH.
- Changes the colour from purple to blue.
- 2 x 10 ml to test 480°GH.