I brewed a 10 gallon batch and poured it into 2 separate BrewBuckets for fermentation. I made a 4L yeast starter and poured half into each BrewBucket. After a couple of days, the airlock on BrewBucket #1 is bubbling like crazy (Hooray! Beer!), but the airlock on BrewBucket #2 hasn't bubbled once...