First DWC grow

I realised great white mycorhyzea is better used as a top feed around the roots, after researching what the microbiotics does I now know they needs a place to innoculate and do their thing, the only thing i noticed whilst i had great white in my water (bubbles) around my roots, it would stick to them makimg the roots look brown scaring the shit out of me with the thought of root rot, once cleaned off with ph water I exclude great white from my solution and only add 40ml around the top roots once a week through the hydroton to prevent bad bacteria. Shortly after there was explosive root growth !!