I use a 5 gallon (barely) glass carboy I acquired at a kitchen supply store, along with a 3 gallon stock pot from same. Next time, I'll get a better pot--bigger with a thicker bottom. I still brew 90% of the time in 3 gallon batches.
Plastic 3 gallon carboys from water coolers are good for secondary tanks.
I'd bought all this stuff before I'd realized there was a LHBS not too far away, now I get pretty much everything there--airlocks, stoppers, bottling supplies, etc.
Check thee guys out, helpful and in the know--
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