Interesting. That's a lot of water, 6 quarts or so. Most sours mixes I've used
make 4 quarts or liters. You could try making your own sours with simple syrup
and lots of citrus, I would guess 7 quarts worth (most sour mixes take up a
quarts volume.
Miss charming has a recipe on her site, and theres one hiding on the webtender
somewhere.
Whats the rest of the mai tai bulk recipe look like?