A glass-made instrument created specifically for examining the CO2 level of aquarium with simple procedure. Add some pH reagent and aquarium water to Drop Checker. Then, set it inside the tank .
* Includes a pH reagent (5ml) * In case the reagent turns yellow from the beginning, due to the low pH value in the aquarium, the reagent color does not change even after adding further CO2. In such a case, please make a water change for raising pH level, and make sure the reagent turns blue or green before resetting Drop Checker in the aquarium.