Stop using CO2?

Is there any time (in the flowering phase) when I should NOT be using CO2??
I'm 2-4 weeks away from harvest and I was just wondering if you guys stop using CO2 at any point, or keep running it until the end?
All opinions welcome.
Thanks

i run mine to the end! as long as they are growing they need it!

ive heard people stop a few weeks b4 harvest . i run my til the end

Run it til the end...just as NGG stated, they grow all the way til the end, therefore they still need it IMO..

ok guys, thanks!
gonna be running C02 right till harvest
Thanks!