K, I have another update for this tank.
I was seriously on the verge of calling it quits not only with this tank, but with the hobby itself.
I don't quit easily, and I have been struggling, pulling my hair out for well over a year because I just never could get rid of this hideous "algae" issue.
I had a lot of advice saying that you'll never fix an algae problem by killing the algae somehow, because it would just come back if the root cause was not corrected. That totally makes sense in MOST cases..
All of my efforts went to trying to adjust the lighting, adding more Co2, balancing ferts etc etc. Nothing worked. It just got worse and worse, so I even tried dosing way too much Excel, tried blackouts, turned up the Co2, put WAY too many plants in there in the hopes of eating up the excess nutrients.. just tried so much. All the while I was losing some really expensive plants.
Finally, FINALLY, I found out that it was not algae at all, but a type of bacteria. In my last attempt (I had decided to throw in the towel if this didn't work) I dosed the tank with some antibiotic used to treat sick fish.
Now, after all this time, it it truly gone. I am finally free of this nightmare, and my passion for the hobby has returned!!! So happy.
I'll take pics and post tomorrow.