Review on ZRDR Glass Drop Checker Kit with 15ml Co2 Checker Solution - The Ultimate Solution for Precise Monitoring of Plant Aquarium Co2 Levels by Brenda Ward

I installed a homemade C02 injector in my plant tank. The indicator works as it should. The liquid changes color from blue to green after CO2 has been injected for a while and back to blue when it is turned off. Nothing complicated, just add a few drops to the bottle and gently tilt. I just filled the bulb to less than 1/3 and it works fine. Put it in the tank, away from the CO2 diffuser, that's it. The suction cups work perfectly. No questions