C02 can definitely help in high temperature conditions, but generally, growth will slow above 83/85.
If at all possible, lower your temps to about 80 and see if your plants dont enjoy it more. I bet they will. And while C02 may help mitigate any ill effects of temperature, it can be a tradeoff because you have to turn ventilation off to run it which lets things get hotter. Unless your running a closed setup. In which case I think no-C02 running 10 degrees cooler would be better. Just IMO, but what do I know - I only have so few posts
If at all possible, lower your temps to about 80 and see if your plants dont enjoy it more. I bet they will. And while C02 may help mitigate any ill effects of temperature, it can be a tradeoff because you have to turn ventilation off to run it which lets things get hotter. Unless your running a closed setup. In which case I think no-C02 running 10 degrees cooler would be better. Just IMO, but what do I know - I only have so few posts