I've joined the pressurized bandwagon too this weekend! Pictures to follow (I'm not at the right computer now.)
I'll add a few tips:
Have something like a stiff shot of whiskey to revive yourself after the pH drops from 7.8 to 6.8 in about 30 seconds! (ok - kidding about the whiskey but not kidding about the pH drop!)
I'm so glad no fish are in the tank. Even an hour later, I was still kind of shocked thinking of "what if". This is exactly why I wanted to hook this system up now, before I got fish. I started this tank in July and it has never been right, so I didn't add fish, and I'm glad I went slowly in getting the tank back on track.
We followed the instructions in opening the CO2 cylinder very briefly (before attaching the regulator) to clear the opening of any possible obstruction. Wow - that's some serious pressure in there! Papers all the way across the room blew around! I tried to set the bubble rate before attaching the diffuser on the other end of the CO2 line. This didn't work because the regulator must have been expecting some pressure from the diffuser and there was none - just the other end of the line lying on the floor. The bubble fluid got forced up the airline a little bit. I disconnected it and cut off the inch or so that got bubble fluid in it, and started again with the diffuser in place. Then so many CO2 bubbles went through the tank. It was more turbulent than the filter ever was. The pH dropped from 7.8 to 6.8 (where I set it) in a matter of 30 or so seconds.
When I change cylinders, I'm going to do this beginning procedure with the regulator and bubble counter with the diffuser in a bucket of water and not in the tank, to make sure everything is set before unleashing it in the aquarium.
Also, the diffuser I'm using temporarily has a check valve in it. I did speak to the local Clippard dealer to get a brass check valve. Since the solonoid is controlled by the pH meter, tank water does rise up in the airline when the solonoid is off. I noticed this before I put the diffuser with the check valve on, but I'd still rather have a brass check valve. Hopefully I'll hear from the Clippard dealer on Monday.