I have learned that Seachem Excel in a 10ml syringe to spot treat works amazingly well. I eradicated all of my BBA in a few weeks by doing that every other day.
EDIT: What filter are you using on your tank? I'm about to sell my Fluval 406 because the flow after cleaning is like a hamster blowing through a straw...
I have been spot treating with peroxide and my preferred method, mechanical removal.
The filter is an XP3 that I haven't cleaned in over a year. It's plenty of flow and reliable. I'm not a fan of Fluval filters though I haven't owned one in at least 7 years. Maybe the quality is better now.