I use pH controlled CO2 injection, so this is quite stable, but still have minor algae outbreaks from time to time (depending on my nutrients dosing habits). Also I assume, algae would respond much faster than a few weeks after stabilizing CO2. I feel (and I can't back this up jet) there is more to it, love to test, but this takes time with only one tank. Tested 40ppm PO4 lately:P now plants are recovering from this shock!
And that is why I (and I guess many others) come to this forum, you're one of the few who tests things scientifically.
As soon as I get my PhD and money to spent, I'll love to do this kind of research as well, till then, I depend on findings of others and my own thoughts to see if that could be right.