We’ll be closed from 1pm AEST Monday April 15, reopening April 22. Save 10% on all orders, applied automatically at checkout. Ends Sunday.

ADA Drop Checker


A glass-made instrument created specifically for examining the CO2 level in the aquarium. Drop Checker helps you to determine the proper CO2 concentration just by looking at the color of the reagent installed in the tank.

To use, add some pH reagent and aquarium water to Drop Checker. Then, set it inside the tank for continuous monitoring. 

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.