I have a white sourdough starter that was fed a constant supply of Anchor Lighthouse bread flour (Australian) and it was very active. As that flour was only available in 1Kg packets it was not cheap for regular bread baking. I have since switched to Laucke Wallaby flour which has received positive discussion on-line and is available in 5Kg bags. I noticed that my starter is considerably more sluggish since the switch to different flour. It has only been two days since the switch. Seeing as both flours are high protein and other factors such as temperature, water and hydration are the same, that it is a matter of the starter culture adapting to the new flour?