IMO, it's impossible to give specifics. Every one does it differently. My best suggestion, just go ahead and try it! Mix feed in a container with enough water so there's plenty of room for expansion, and the resulting mix is about the consistency of runny oat meal. Add some ACV with the mother, or don't... it really doesn't matter. let it sit until it bubbles, stirring 1 - 2 x/day. Feed it to the girls. If it's too soupy at this time, add some dry feed to it to make it a consistency that you like. There should be some FF left in your container. Add more water and feed, stir well, and wait till it bubbles. Start with a small container, and play around with the consistency until you get a consistency that you like, then progress to the size container you want/need to use.
After repeatedly answering the same questions in lenght, the FAQ was born. The folks on the other FF pitched in and contributed to post with feedback. You'll see several places where I've linked back to that thread. There is a HUGE amount of info, including linked studies, on that thread. 
