This is definitely a you get what you pay for piece of equipment. Particularly the regulator. I started with a Milwaukee. The bubble count fluctuated causing my controller to try to stop it with the solenoid - except that the solenoid leaked. So, my cell phone is going nuts with emails in the middle of the night because the tank pH was dropping way low. It just about buzzed itself right off the nightstand. So, scrap that and build a good regulator with a good solenoid and a good needle valve.
Then, the flow was not steady due to the crappy ball valve I had on the output. Scrap that and replace it with a good quality needle valve.
To be honest, if its not been one thing, its been another for me going on the last 8 months or so. Its only been a few weeks since I've finally got all the upgraded parts installed and everything turned back on. Since then, its been great. Set it and forget it till the tank is empty or the media is used up. This, I really like.
So, its been a process trying to get mine running and dialed in in a reliable manner. Just be careful along the way because if things go wrong, they can go wrong in a big way.