You can go above the 1000 PPFD mark easy. It is however strain dependent.What ppfd or par range is best wen supplementing co2 in flower - co2 stays between 1200-1500ppm
Would you hit 800ppm the first week of 12/12? Or like 3 weeks into it?^
I'd start at 800 PPFD and work my way up until I see hints of light burn. I'm guessing that 1200 will be the sweet spot for mature plants.