API GH & KH Test Kit Fertilizer Components A-618-B black air duct:

A-618-B black air duct:

Patent self-floating design can automatically adjust water-level without effecting the function of filter system

Dosage should be determined by your water test results and corals daily consumption

salamander

API GH & KH Test Kit Fertilizer Components A-618-B black air duct:When keeping freshwater fish and plants, the general hardness (GH) and carbonate hardness (KH) of aquarium water should match their natural habitat. The API GH & KH TEST KIT helps you duplicate the natural habitat of your fish to prevent stress, keeping them healthy! Contains 2 test bottles, easy to ready instructions, and glass test tubes