Carissa, thanks for clarifying. I do want to keep the fish I have, so it looks like water changes are mandatory. I will also stick with standard daily dosing pf Excel to help out the plants (and aggravate the algae). Perhaps you or Tex Gal could help me figure out the correct EI dosing for a low-light, non-CO2, 55 gallon tank (containing probably only about 40 gallons of water)--the articles I've read say to dose "less often" for low light/no CO2 but don't give specifics on how much less often.

Homer, thanks for your input. I read the post of Tom's that you linked, several weeks ago; it's the post of his I mention in my first post in this thread. It seems a lighter fish load than I currently have may be necessary to be completely successful with that method. Since I tore down my tank completely in September to convert it to live plants, I would rather not tear it down again unless I have no luck in getting the BBA under control with more conservative methods. I've cleaned up and pruned away all the visible BBA, added more plants, added a bit of Sea Chem Equilibrium and KNO3 to the tank, added another filter, and will go back to weekly water changes. Everything looks pretty good right now; time will tell if more drastic measures will be needed.