The Dymax Crystal CO2 Drop Indicator allows aquarists to easily identify when the correct concentration of CO2 has been achieved in the aquarium. Available in small and large sizes. A Simple and Accurate Method for Monitoring CO2 Levels in a Planted Tank. The Dymax Crystal CO2 Drop Indicator is built from high-quality glass and easily monitors CO2 levels in planted aquariums. The solution changes colors to indicate whether an excessive, optimal, or insufficient amount of CO2 is injected into the planted aquarium (when used with the CO2 Indicator Solution, sold separately). Highlights: A simple method for monitoring CO2 levels in a planted tank Ensure CO2 levels are stable pH reagent solution, sold separately Included in the Package: Glass Drop Checker Suction cup Dimensions: Small - 2" x 1" Large - 2.5" x 1.2"
