Primary carboy size

[Turfmanbrad]

I have a bucket for a primary and a 5 gal glass carboy for a secondary. I'd like to have another primary, so I want a carboy. I see there are 6.5 gal glass ones that are recommended, but only 6 gal better bottles. I'd prefer the better bottle material, but is 6 gal enough for headspace? Thoughts, experience, thanks!

 

[ETCS]

It will work fine. I have one glass carboy and 4 better bottles, won't go back to glass. Just make sure you use a blow off tube.

 

[HolyDiver]

Ya, your likelihood of needing a blow off for the 6 gallon is a bit higher.