CO2 regulator woes

[slojmn1]

Help me to understand why I have such a difficult time with these darn regulators and needle valves. I set up my new regulator and pH controller a week ago. I followed all the instructions, this is my third regulator by the way. I set it at the recommended working pressure between 10-15psi on the right guage. The CO2 bottle is full, no leaks. I have tested for leaks a number of times. Okay, so I find my pH of the effluent rising , the solenoid kicked on and no bubbles coming out of the line into the reactor. I crank up the working pressure bubbles fly out of the line and into the reactor. I crank some more and bubbles continue to come out at a fast rate. I close the needle valve, bubbles continue to flow based on the working pressure guage, as that goes higher the bubbles flow faster despite the needle valve being closed. I crank back down to recommedned working pressure and the bubbles flow freely until, I am assuming , the CO2 is empty from the regulator. The needle valve is doing nothing. If its closed or open the bubbles are totally dependent on the working pressure guage. No bubbles are coming out when it is below 25 psi. What am I doing wrong?

 

[slojmn1]

Found the problem. It appears the Co2 is building up in the reactor and is causing excess pressure of some sort. I have no clue how to remedy this or why it is happening. Any help out there would be great. I disconnected all of my lines and as soon as I took the check valve off of the CO2 line between the bubble counter and the Co2 bottle I had a shower of excess CO2 and water from the bubble chamber come flying all over me. Then I could hear all the CO2 venting out of the reactor through this opened up line. What is causing this build up of CO2 in the reactor?

 

[slojmn1]

To be more specific, one of my Check valves appears to have gone bad and was not letting CO2 past it into the reactor except for a trickle under very high pressure. Swapped out for another check valve until I can see if I can fix this one. The system is running normally again.