ISTA I- 690
An easy and simple way to indicate the level of carbon dioxide in water. With a convenient nozzle, you can place it anywhere in the tank and in any position. It is made of high-quality clear acrylic.
The fluid indicates 3 colors:
- yellow -the level of CO2 in the aquarium is too high
- green-CO2 level in the norm
- blue-CO2 level too low