mycorrhizae in dwc and ph

Alright then a bit of a strange 1 ive always ran sterile res and lately ive switched to living res so since ive been adding bennies my ph is climbing over night to 7-7.5 everything looks healthy above and below and i have heard a couple of people say over the years that with mycos you dont need to be as careful with the ph but this is a big amount is it because the fungai converts and fixes any changes would really like to know???? anyone care to enlighten me please

anyone???