| | Re: CO2 system suggestions for a 75gl tank
If you set the regulator and needle valve to the bubble rate that gives you the amount of CO2 in the water that you want, it will remain that way until the CO2 tank runs out of liquid CO2 or until the solenoid fails, if you use one. But, if you use a pH controller you have to set the needle valve and regulator to give more than enough CO2, or the controller never does anything. Then if the controller or solenoid fails too much CO2 is supplied continuously to the tank, killing the fish. It is safer without the controller.