co2 help

anyone ever wait to turn on co2 till after the stretch? I consider myself pretty exsperienced grower but had never grown with co2 till last run. Things got out of hand real quick. I had a terrible grow. I'm thinking of of 2 options 1 waiting till after the stretch to turn on co2 or 2 only vegging for 2 weeks in stead of 4. Only thing about 2 weeks is your limited on getting clones? give me your thoughts

unless you are growing from clones its impossible to stop veg at 2 weeks

In General your co2 PPM should match your lights PPFD at all times. There is no right time to supplement it in my personal experience. Not supplementing it for any period of time is detrimental to my setup as my ambient levels drop below 400 PPM without a co2 generator. The basis consensus is Cannabis Plants (c3 plant) can only uptake as much light energy as they have co2, so if your running 1000 PPFD lights and have 400 PPM co2 your basically throwing 60% of your light away as the plants will not be able to effectively utilize it.