I did get the Co2 situation stable for now. I was having problems with the solenoid leaking so I removed it a few days after initial setup so I'm injecting C02 24/7 for now at a bubble rate of 1 per second. I also removed the diffuser because it wasn't working well. I've always had good luck with powered reactors so I decided to try one of those Venturi Reactors that Tom Barr designed. The whole setup has been running "dialed in" and untouched for the last 10 days. Co2 pressure still holding steady.
Here's a pic of the one I built:
It's working extremely well. It distributes minutely small C02 "mini bubbles" throughout the tank that flow in the current of the tank and settle on the leaves of the plants. These are smaller than any diffuser that I've seen in action and the nice thing is that it needs virtually no maintenance in comparison to a diffuser.
It's powered with this
http://www.drsfostersmith.com/Produc...5&N=2006+22768
It is the one on top of the page. It is smaller than any power head measures approximately 1-3/4" x 1-3/4" x 1-3/4" and has an adjustable flow rate of up to 60 gal/hr. A nice feature is that it has suction cups to attach it to the glass and it can also run for 30 days dry before failure.