I think 100 is too high--try 90 degrees for the hot spot at one end because they really don't need all that heat. Decrease it by 5 degrees each week, but also watch them. Your brooder will be way too small in 2 weeks. Mine was just like yours but 48 x 48 inches, and it gets crowded for just 35 chicks to stay in for 5 weeks. Nice job on the brooder.
90 degrees is too cool for the 1st week for quail!