Rough calculation of hydration:
starter has: 100 % = 1 kg water is 500 g
flour is 800 g
leftover bread has > 300 % = 4 kg water
is 320 g, flour is 800 g
dough water is 3.5 kg flour is 9.5 kg
From recipe:

Bakingtemperature: 160 C (320F), dropping
to 120 C (248F)
Bakingtime: 2024 hours
from Handbuch Sauerteig:
Sourdough <= 10 %
baking 16  24 hours
temp 100  120 C = 212  250 F
Retsel steel burr 1/2 turn open is 27 % coarse,
73 % sifted
1 turn open is 81 % coarse, 19 % sifted
sieve has 1 mm sqare openings