I too had a tough time with BBA.....some say it infests tanks with high carbonate hardness.....
in the end....I gave up and left it alone.....as as my plants grew like gangbusters.....they mysteriously dissappeared...I still have a few here and there growing on rocks....but at least its under control right now...
Ehiem Pimp # 88
29 Gallon PC 4WPG,Ehiem 2224 Pro, Pressurized CO2, Power Reactor, Eco Complete
75 Gallon PC 3.5WPG,Ehiem 2226 Pro, Pressurized CO2, Ext Reactor 1000, Eco Complete