I reread Chau's informative and helpful thread at http://www.pizzamaking.com/forum/index.php/topic,10658.msg94705.html#msg94705
in which he established a conversion factor between ADY and his natural starter of 15 grams = 1/8 teaspoon ADY. Then, using the simple mathematical expression he gave in Reply 109 in this thread (at http://www.pizzamaking.com/forum/index.php/topic,11578.msg107357.html#msg107357
), I came up with a a value of 12% for the amount of natural poolish to use in relation to the total formula flour. For this calculation, I used 0.40% IDY, which is what you normally use for your basic Lehmann preferment dough formulation. Since you are using a natural poolish, with equal weights of flour and water, and because of the many other variations in natural preferments, including readiness, type/composition and fermentation protocol, the difference between 12% and the value of 14.39% I established in Reply 111 using the cruder conversion method perhaps doesn't mean a lot. However, at such point as you decide to make a larger batch of dough (e.g., five dough balls), you have the option of redoing the dough formulation I gave you in Reply 111 but using Chau's value of 12%. In the meantime, you might even learn something from your current experiment that might require or suggest other modifications to the dough formulation.
What I have been trying to do thus far is to see if I can come up with a naturally leavened version of a dough formulation that matches as closely as possible the current Lehmann commercial yeast preferment dough formulation you are using but with a different fermentation protocol, as you are now testing with a single dough ball. A major advantage of this approach, apart from hopefully getting better tasting crusts with improved texture, is that the physical aspects of the exercise, such as number and weights of dough balls (e.g., dough batch size) and pizza size (16"), remain the same. Potentially, the major challenge may be how to adapt the dough formulation and fermentation protocol to your one-day-a-week market environment without having to constantly feed your cultures as you would any other pet. You will also have to contend with the vagaries of weather and ambient temperature, as you are now experiencing with the single dough ball.
Sometime when you have your starter culture fully active and ready to use, it would be interesting to know how much a cup of that culture actually weighs, that is, is it around 9 ounces, as Ed Wood uses as a conversion factor?