Allows you to monitor the CO2 level in your tank from any angle.
With smart design to prevent any chance of spill of the indicator solution.
Reusable color chart sticker provides convenience in location change of the sticker.

How to use:

Take apart the CO2 indicator
Add 1cc of indicator solution to the reservoir then reattach the CO2 Indicator firmly.
Submerse the CO2 indicator vertically and attached to the desired location inside the tank (the position to cover the suction cup) to read the CO2 level in your tank.
Change solution every 2-4 weeks. Solution change at water change is NOT necessary.

ISTA CO2 Indicator - All Angle View