I am by no means a pro at aquarium co2, but I do know a few things about pressurized fittings and attachments. It is possible that you could be tightening your fittings too hard. Do you have a seal between the valve and the fitting? If not, try one. They are cheap. Also, if you know you have a prob with the regulator, why not return that junk to the guy you bought it from and get a knew one? The easiest way to check for leaks is to make a mild soap water solution and put it over all the fittings. If it starts to bubble, you have a leak. You may also want to invest in a standard co2 bottle. A 10 to 20 pound bottle will hold much more co2 than a small paintball bottle. You can have these filled at most gas and fire extinguisher service centers. Hope this helps some.