Originally Posted by abracadabra
Why? I'm assuming you've tried both since you know what size stopper fits.
I like using Better-Bottles as a system. To use one alone is great, but as a system, using the accessories, it allows me to perform an oxygen free transfer from primary to secondary. The CO2 produced during primary is used to purge the air out of the secondary using Better-Bottle's ported closures, racking adapters, valves, dry air locks, 90˚ barb fittings and a couple of lengths of tubing. After the primary, a quick switch of the tubing allows for oxygen free transfer. It may very well be overkill, but I like it!
I found a supplier that specially drills a #10 stopper in order to fit a length of 5/8 tubing for use as a blow off tube. That is the only reason I know what size stopper fits. That blow off setup can be found at Hearts Homebrew
Honestly, when I first discovered Better-Bottles, the thought never occurred to me to use anything other than all of the solid PET, o-ringed accessories made exclusively for them. It just seemed to make more sense to use them as a whole system. Again, that is just one persons opinion.
A detailed description of the above diagram can be found at Better-Bottle's
The bags of water are just to allow me to see the bubble rate for the Dry Trap Air Locks.