Whenever someone has BBA I always ask if they are dosing Iron. 😄 I say cut the Iron back to once a week but keep the other ferts steady and see how that looks after 3ish weeks. As someone else said raising CO2 might actually help.
You can also spot treat with Peroxide, Excel, Easy Carbon, etc and get some Algae eaters will take care of the rest.
Edit: Do you have lots of red plants? You can get plants red without dosing extra Iron. EG already has some Iron so you may not have enough plants actully using all that Iron.