The solenoid valve does not let gas into the aquarium.
If the device is not connected to electricity, it will not let gas flow into the aquarium. Turning on the power will start the device.
The device is loud and emits a nuisance.
Check the tightening of the black, perforated nut and make sure it is tightened well. If the problem persists, use the complaint procedure.
The carbon dioxide quickly ended up in my tank.
Check that all components of the CO2 kit and hose connections are tightly screwed together.
After disconnecting from the power supply, the solenoid valve lets a small amount of gas into the aquarium. After a dozen or so minutes it stops.
This phenomenon is caused by the gas pressure that has been left in the system. If the amount of gas is small, after a dozen or so minutes the pressure in the CO2 system will decrease and the dosing to the aquarium will stop completely.