See my post from a page or so ago. I'm still on my first set of o rings since April. I bought a second cu in June and in still on the first set there too. I sometimes see the o rings have expanded during my process, I think that mostly happens when the ultrasonic cleaner is super warm, but that's the worst I see and they always return to normal size when they dry.What are people's experiences with O-rings after a while in ISO, do they lose any quality over time?
Fwiw, The manufacturer includes 2 sizes of o rings, this is to get around variances in the ID of the stems.