Are you talking about the "Plant-Gro CO2 Natural System"? I bought one of
those yesterday and it's doing the exact same thing.
It's not elegant, but it's probably a good thing. Bubbles, while remaining
more or less stationary, get more time to disolve in the water, I guess.

Did you buy only the diffuser (bubble counter), or the whole setup? I
bought the whole set-up, but now I'm thinking I probably should have bought
only the diffuser (Bubble counter) and DIY the rest.

I don't know about you, but I was a bit disapointed by some part (of lack
thereof) of the kit. No check-valve? The tube seems made of vinyl(?)
instead of a better material like silicone.

"Andrey Tarasevich" wrote in message
...
I notice that instead of going all the way up CO2 bubbles are collecting
in my
new Hagen Nutrafin diffuser forming larger bubbles that just sit there all
the
time. I tried forcing them out of there but eventually they reappear.
Meanwhile,
I saw a working setup in my LFS and it didn't have any bubbles stuck in
it. I
also read somewhere on Google that this is normal for freshly installed
diffusers and eventually this issue will go away. Did anyone experience
this
problem with their Nutrafin diffusers? Will the diffuser eventually clear
up?
And if it will, what's the physics of this process? I.e. what exactly is
going
to change so that the diffuser will no longer trap and hold CO2 bubbles?