What is the final say in when to start Co2 injections?

Some here say that Co2 is not worth it in veg but great in flowering.

Also I heard to stop using Co2 the last 2 weeks of flower... is this true?

__________________
I wish I could grow, but I respect the law of my authority figures.

Co2 injection has its share controversial sides to whether its worth all the trouble, I have had my issues's of "what a pain in the ass" I have to admit that I do like the way the plants behave in a co2 treat room but as to the finale results of "THC content, potentency, Size of your fruit (Bud), the important stuff, I can't give to those type of results but can tell you the difference that I have seen in my experience in the pass and present. Use the same gene plant through the year. With co2, the size of the leaves get big like dinner plate size of bigger, you have check your water and nutrient level more often, if you are growing in pot in medium or some sorts, you have to add another water day (plants soak up nutrient solution faster) the leaves are standing more out or up, deeper color, plant tends to tolerate a higher level of nutrient (EC,PPM) branches are thicker, buds seems to be more meater, firmer, and harvest is always a week to week and half sooner (adjust fedding schedule) same results with co2, like clock work. Yes, you should stop using co2 at 2 weeks, some do it at 3 weeks. The extra carbon build up in your buds which will make you have that harsh cough, you would just have to cure it longer, if you make hash, you have to work it more to get the carbons out,(nasty cough) Is it worth it ?, well, lets put it this way, Iam not running co2 right now with my set. At least you can but bugs to sleep, catch a spider or what ever bug place it in a jar, place the co2 tube in the jar, in about a minute they will fall asleep. They wake up in couple hours, be nice to them, they all have a purpose exept of course that doen't apply to the invaders of our favorite plants, becuase those must die!!
Hope this helped alittle.
CRK

I use co2 in vegg and flower up to harvest. This is what i have read-
"CO2 is an odorless, invisible, and non-flammable gas. It is also safe for humans in the maximum concentrations recommended for plant growth. The average level of CO2 in the atmosphere is about 300 PPM (parts per million). If the level decreases down below 200 PPM in an enclosed growing area, plant growth slows to a halt. Through the years of testing and research, the optimum enrichment level of CO2 for plant growth has been agreed to be about 1500 PPM. With CO2 enrichment, under good conditions, plant growth rates and flowering will increase 20-100%. CO2 can be used from seedling right through harvest."
But like Green Gaint stated Look how big the dinosaurs were-they lived in 12x's as much co2 as us currently. Do your research and decide if its a road you want to travel, really.

__________________

Well I am def going to be using Co2... I always have, so I don't know if it is actually doing anything, but I'm sure it is. I was just wondering if I should start using it soon as my seedlings are up and at em'?

__________________
I wish I could grow, but I respect the law of my authority figures.

I started with da cheap method, Sugar/yeast/warm water,shake, done Google co2 diy.

__________________

If you re-read post #3 this is from the co2 conversion calculator write up I copied and pasted it says from seed to harvest-hope this helps.

__________________