For what it's worth...
Preparing a microbe tea outside of the res is not necessary in an ebb and flow setup. We do it in DWC when the system has been shown to be prone to root slime because the slime can feed off the food before the bennies and outgrow them. In my experience, prevention of this type of slime is inherent to an ebb and flow system as the roots sit in air most of the time. So, for ebb and flow, breeding them in the res makes sense. Just dump in some GW powder and some food every once in a while and be done with it.
Of course the tea would offer a few advantages. Using EWC you would get a more diverse microbe community. You wouldn't have to add food or housing to the res. You have a cheap supply of freshly active microbes in case you need to refill a res on the spot. Plus the great white would end up lasting longer, since we only use half dose in the tea, and then use the tea to inoculate gallons and gallons of water. If none of these are important to the grower, then no need to complicate things.
The product at fungi.com is exactly the same as great white, but without the bio-stimulant package or the plant vitamins.
