CO2 Drop Checker level indicator
It indicates the level of carbon dioxide in water in an easy and simple way.
Thanks to the convenient suction cup, it can be placed anywhere in the tank and in any position. The device is made of high quality transparent acrylic.
The liquid indicates 3 colors:
yellow - CO2 level in the aquarium is too high
green - CO2 level normal
blue - CO2 level too low
Ista I-691 is used for refilling the fluid;