I don't think a chemical solution is the way to go. Rather, you need to find the underlying cause of the excess algae you are experiencing. An explosion of algae is usually caused by bottoming out or an excess of one of the nutrients needed for plant growth. More specifically, the areas of concern to look at are: Light, CO2
, Nitrogen (nitrates), Phosphorus (phosphates).
For BBA... it can be a big time hassle to get rid of it. Are you injecting CO2
at all? I have found increased and steady CO2
injection is a great prophylaxis for BBA.
There is one chemical I would suggest for ridding your tank of it, since it is already present: Seachem excel. You can put it in a medicine dropper and inject it right over the plant leaves that have the growth. After a few doses (over a couple of days), it will turn pink and die back. The other alternative is to use H2O2. It can be very effective for killing BBA.
In the mean time, we can help determine the underlying cause if you post your current fert dosing regiment, the type of lighting (and duration), and whether you are injecting CO2
(and how are you doing it if you are?).