What might cause uneven carbonation?

[Geordan]

Hey all!

I've got four kegs in my fridge at the moment, all connected with a manifold to the same regulator. Two of the kegs have been in there for about two months, and they're slightly overcarbed (for bottling); two more have been in there for two or three weeks, and they're significantly UNDER carbed. I'll confess I thought that after two weeks that they would all have come to the same level of carbonation, but there's still a distinct difference.
Does anyone have any insight? Thanks!

 

[BrewChem]

O-ring leak(s)...?
Pressure regulator defect...?

 

[Geordan]

I did a quick check for leaks with starsan, so if there are any, they're slow and insidious; everything's driven by the same regulator, so I don't think that's it.

 

[day_trippr]

I've always found it takes three weeks for a full keg to reach perfect carbonation. They'll usually be good enough to dispense after two weeks, but they're even better after that third week...

Cheers!