Are high temps necessary for Co2 enrichment?

You don't want to be over 90, ever. 85 with 1500ppm is optimal, if you're running at 80 during lights on I'd just set your co2 for 1000ppm and you'll be in the perfect range to utilize all of it without wasting any.

ya my temps run 75-82 and I run about 900ppm on the Co2, seems to be working out well.