As the amount of dissolved CO₂ increases, the pH level lowers to become more acidic. On the other hand, as the amount of dissolved CO₂ decreases, the pH level increases to become more alkaline. Drop Checker uses this relationship to show the concentration of dissolved CO₂ by changing the color of pH reagent. It is not accurate to consider changes in dissolved CO₂ amount simply by measuring pH level of aquarium water because stones and driftwood which contain substances affect the pH level. Drop Checker has a layer of air inside and allows only the changes in CO₂ amount to be reflected in the color of pH reagent in the check ball. As can be seen from these features, Drop Checker has a unique design which offers outstanding functional roles.

* 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.