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