ISTA Glass Indicator

The ISTA Glass CO2 Indicator effectively and accurately monitors CO2 levels in your fresh water tank. Achieve appropriate CO2 levels in your aquarium to reduce damage and stress to your fish. The glass CO2 indicator includes a suction cup for easy use. Easy-to-read color changes make knowing how to adjust CO2 levels in your underwater world a breeze. The indicator is made from high quality clear glass and is specially designed for a spill-free experience. The solution will turn colored to give you a clear reading. If the solution is yellow, there is too much CO2 in your tank. If the solution is green, you have enough CO2 in your tank. If the solution is blue, you don't have enough CO2 in your tank.