What size tank, how much light, do you have pressurized Co2 and do you add ferts?
I believe BBA is a result of an imbalance of light, Co2 and Ferts. Usually it is a case of too much light and not enough Co2 and ferts but regardless there must be a balance. It will grow on some plants, in particular java fern, anubias and some crypts. It seems to like plants that have a stiffer leaf. When I frist got into planted tanks 4 or 5 years ago I thought more light the better. Boy was that a mistake. After sevearly cutting back on light and adding Co2 and ferts the situation improved dramatically.
You can use Seachem Excell to spot treat BBA. Use a syringe, turn off the filters and squirt the excel directly on the BBA. After a few minutes you can turn the filters back on. In a day or so you will notice the BBA change colors, and it is dead. This won't solve the problem though so if you don't fix the cause it will certainly come back again.