Hi Eric. My husband is from up around Milwaukee and all these references to "bubblers" has me a bit confused. Is this like something that aerates the tea, or mixes it?
You are correct in that it is something that aerates tea. Set-ups start from around 5 gallons. It is part of a way of making compost tea that encourages microorganisms (AACT) - Actively AeratedCompost Tea. The set ups are usually composted of some bubbling device like you might get in ponds, a bucket and then various ingredients being added, the main one understandably being compost. Some people suspend the compost in muslin or a stocking in the bucket. Hope that clears it up.
If you are doing it I would recommend you stir also. I have included a photo self-plagiarised from my book.