DENNERLE CO2 long-term test Maxi and pH

The complete set enables permanent and precise control of the CO2 content in your aquarium. It contains a test container, a CO2 Special-Indicator and a six-color comparison scale. Using the six-color comparison scale, you can read off the CO2 content directly in milligrams per liter. This makes it very easy and safe for you to add the right amount of CO2.