If you want to make most efficient use of CO2 enrichment, you have to provide MORE of everything because fast growth comes from faster chemical reactions in an environment with no limiting factors (in practical application, indoors you do have one, and it is light).
First, is your grow already perfect? If not, forget about the CO2. The only exception is if your only problem is slightly elevated temps and insufficient ventilation, in wich case CO2 can help.
Now, do you have a lot of light? What is your space, and what is your light?
NExt, are your plants in good health? Are you comfortable with your feeding, and can you diagnose hunger/burn/lockout correctly?

CO2 enrichment is most effective in a VERY bright space that is slightly warm, like about 85'F.