After 7 long days, Thing 1 and Thing 2 are looking and acting like living, breathing starters. Thing 1, the indoor starter almost tripled itself today, and Thing 2, the outdoor starter doubled.
As I expected, they are behaving differently, but I actually expected Thing 2 to be more energetic than Thing 1. I guess I expected the outdoor microflora to be more lively than the ones in the house.
I'm going to keep them at 100% hydration for a few more days and then switch them to 50%. I want to see if I can expand them both enough to bake with them this weekend.