H2O2 never eradicated it, I tried a few times.
Algaefix does kill it all.
Root issue needs solved 1st, mostly CO2 issues.
I understand that. Before I left, I increased CO2 as well as cleaned my diffuser, decreased photo-period, added a 1.5hr break in photo-period midday, thinned out what needed thinning, trimmed everything pretty heavily, I might also try raising my light a couple inches higher in the canopy to help reduce BBA growth as well. putting in my glass top has definitely had an effect on light intensity and BBA growth has slowed, but I still have 2 or 3 inches more that I can possibly raise the light to decrease or halt its growth. While I've been gone I've had someone coming to fertilize the tank each day and do water changes according to my normal maintenance schedule. I wish I had found your advice about AlgaeFix before I went through all that trouble with the H2O2. It worked remarkably well, apparent after the 2nd dose (6 days, dosed on day 1 and 4). I just did a 3rd dose to be safe. I was actually able to catch all of my shrimp and place them all in quarantine so I had no casualties.