Hey that was my post! Sweeeeet!! However, contrary to the claims made by me in that thread, there really is nothing wrong with the glass diffusors in a DIY situation. It's just a matter of getting it right... Curious, what type of hose are you using? Is it the silicone type or the cheap, stiff hose? I just wonder, because, I can't understand how you are getting leaks around the silicone tube (if that's what you are using). You can also buy CO2 specific hose, if you are prepared to fork out a little more, but the silicone should be fine...Look at this thread: Check out post #89 It works.
Do a test. Unhook your diffusor and just let the open hose sit in your tank. This is just to see if you are actually getting any gas production at all. If this proves OK, you are one step closer to success. Did you follow my advice in your other Thread (actually,why start another thread on the same topic??) and get rid of all the unnecessary fittings? One other thing. Do you have more than one diffusor? I bought three off ebay, it took me a week to work out that two were, not duds, as such, just less operative. I now just reuse the same diffusor, cos I know it works well.
There really is no reason for you to be having this much trouble. I think you have overlooked something... Just relax and try to break the system down into it's various parts, in your mind as well as hands. Eliminate or fix each area, step by step, and be patient... We don't want you buying fake plants, y'know!!