Wow that's a lot of bacterial slime! Good thing you caught that, if it was to build up more, imagine if the BP reactor got plugged.
I have always been dosing vodka but never any bacterial supplement, I found that even vodka alone can produce a white slime film if used incorrectly. From Sunnyx's tank MB7 looks like it can perform miracles. I'd be interested in seeing the long term results and I might give her a try.