Mediaone what is your setup and routines?

All methods suggested here will get rid of BBA. This I know because I had a bad outbreak of Co2 back over a year ago now in my 90gal. The cause then was straight lack of co2 as movement is never an issue for me due to my sump setup and pump flow. I had taken out all the plants from my tank put 1 cap excel in a 5 gal bucket, let it sit for 2 hours, once plants were replanted I double dosed for a week just to get rid of any stray BBA. I have never had a BBA outbreak since getting my Co2 in check and using the misting method which was via R5K initially, then TBarr venturi style reactor and now Mazzei 384 injection.

If you have done all the suggested methods, Co2 is where it's needs to be and still getting BBA then it makes me wonder if you have flow in check? Iron is not an issue IME as I dose fairly high Iron everyday of .20ppm. You use your fish gasping as means to determine high co2 level I use that to determine you still might have low flow issues in your aquarium because if you had good flow and surface movement you will not have gasping fish...well at least mine aren't gasping just 'lil' nosy

In my 20 gal tank I have very high Co2 levels as it gets 24x7 Co2 and none of my fish shows any stress or gasps at the surface. I do have good water movement throughout the tank and surface movement to match...see below




Let us know your tank config, routines, param's...... etc