[Robert Hudson]

I've got a JBJ, my favorite thing about it was that the 10 psi I run my system at wasn't enough to get CO2 past the flapper check valve. Had to drill it out. Quality stuff.

You might have that problem with any check valve initially. I have found you need more pressure the first time you use the check valve to open it up. The JBJ bubblecounter screws onto the needle valve assembly, and it has a rubber gasket to prevent leakage. You do not have to tighten it very hard to get a good seal, over tighten it and you can break it rather easily, but there can be manufacturer defects which can cause leakage around the fitting or cracks in the plastic. Thats why I find it easier to use a cheap inline bubblecounter. Any plastic bubble counter will have its stress point. Glass is even worse. These ADA and ADA rip off solid glass bubble counters... you have to be real carefull how much force you use when putting on the tubing. It can be an expensive mistake if you exert too much pressure.