API TEST KIT FW/SW CARB HARDNESS

KH: Carbonate hardness, also known as alkalinity, is the measure of carbonate and bicarbonate concentrations dissolved in water. These minerals are present in municipal, well, and bottled water. Carbonate hardness helps stabilize pH in the aquarium. An aquarium with a low KH level will tend to be acidic. Aquariums with very low KH are subject to rapid pH shifts if not monitored carefully. Water with a high KH level usually has a high pH.

GH: General hardness is the measure of calcium and magnesium ion concentrations dissolved in water. Hard water is high in calcium and magnesium, while soft water is low in these minerals.