There is a website I have read, that shows some very good information about teas in general.
Microbeorganics(dot)com
He sells a similar design, but calls it an airlift brewer.
But he actually uses a microscope and goes in and looks at the diversity with different ingredients.
While he doesnt have the vortex, it does use the waterfall to create the DO instead of traditional air stones.
Cool, thanks for the precision and it make sense, DO in a recycle by vortex system like this should keep enough in this semi close systemā¦ Water movement also helpingā¦
Great idea and great build my friend 
I should give this vortex brewer a deeper look and understandingā¦ Lol 
There is some to chew on, in this link, thanksā¦
Yea check it out, the build is very easy, amd there are many ways to tweak it to fit your needs.