Hey guys, newbie here. I am piecing together a kit from items that were giving to me. I have a 5 gallon glass carboy. I see all the beer kits are for 5 gallons and require a 6-6.5 gallon carboy (to accommodate for the expansion). Any suggestions or do I need to get a 6.5 gallon carboy? I would like to brew I mid sized batches. 3 to 4 gallon yields if possible. Thanks!