I get the 30L size, because it is 8 gallons. *Just* enough to do a boil for a 5 gallon batch.
I don't get the 50L size. It is 13.2 gallons. It is way more than you need to do a boil for a 5 gallon batch and it is too small for a 10 gallon batch. A 10 gallon batch will start out the boil as at least 12 gallons, if not more. A 13.2 gallon vessel almost assures a boil over.
