Actually the corrected chart is this one:
The chart you posted was before Hoppy realized the Lux to PAR conversion factor was off making it appear the light did much better than it really does. It still does a good job for a cheap fixture.
The updated chart now makes it appear that the diamond plate fixture is not that much better than a regular white painted surface shop light which you might be able to get cheaper. Although I really like the look of the diamond plate over those shop lights. On this chart double the PAR for the white painted fixture because as charted it's only for 1 bulb lit not 2 as in the diamond plate fixture (makes the diamond plate fixture look much better until you realize you're comparing 2 bulbs vs single bulb). I still think the diamond plate should do much better than the white painted fixture because the reflector is so much better. But for some reason it doesn't appear that way on the chart.
As to how much light before needing pressurized CO2, I'll quote what Hoppy wrote:
I don't believe there is any consensus about the definition of low, medium and high light. But, here is my definiition, subject to, and almost certain to change:
Low light - 15-30 micromols of PAR - CO2 is not needed, but is helpful to the plants
Medium light - 35-50 micromols of PAR - CO2 may be needed to avoid too many nuisance algae problems
High light - more than 50 micromols of PAR - pressurized CO2 is essential to avoid major algae problems
I've got a weird setup or I'd provide more info on my results using the diamond plate fixture.