What? No GSA too? That is way more light than you need. I was at 4x54w on my 72 gal and until I cut back my photo period to 8 hours and only 3x54w I has BBA and GSA pretty badly. And all plants still do great. That would be a good start. Also make sure you fert well, macro and micro, and have a good amount of plants to outcompete the BBA or you'll be forever fighting losing battle.