I went back to the beginning and reread each of the posts. I would like to thank you for your advice.
So what finally killed the algae? To my mind, what impressed me as most useful were the 50% water changes (8), which certainly reduced the Flourish Comprehensive I had been unknowingly overdosing. Dosing can be hard - it's at the beginning when you know very little that you need the knowledge.
I have been working more on the Flourish dose, doing the math and the conversions. For my tank it looks like it's about 10 or 11 drops.
MY 10 GALLON PLANTED TANK:
2 x 10W CFL; Fluval U2 internal filter; MGOCPM/black sand cap
A Silent Cycled Tank