Ok CO2 is not effective until 1000-1500 ppm. The growth is not linear, lesser than does not help more of an on off thing.

Studies at University level and commercial grows have proven temp above 75 degrees effects potency from degradation of the volitile organic compound produced by tricomes. Some strains were reduced by 20% from 80-84 degrees.
It looks like you have a huge space. hopefully it is stable in regaurds to humidity. that is about the max and most run 47% to 35% in late flower if you have huge buds.
Good luck