I am use a pop bottle at the mo while I await a new bubble counter. It's unsqueezable form the pressure but not popping.
I don't agree with the 'high bar' need of these diffusers. They used to say that you couldn't run a disc diffuser with a yeast setup as it couldn't push enough pressure but I used one with a single Nutrafin kit and it worked fine.
Similarly I am only pushing 1.7bar with my inline Up atomizer. this is one that people suggest needs much higher bar, yet it works fine