That is strain dependent. There is a fairly current scientific paper from the wonderfull folks at the University of Mississippi dealing with the photosynthetic responce of Cannabis sativa to variations in photosynthetic photon flux densities, temperature and CO2 conditions. They found 30c/80f optimum, and that temp was related to what the strains' genes had adapted to in it's natural enviroment. Cannabis indica would probably be less just because of it's normal area of developement is cooler. Hybreds and crosses of course will fall in between.
Originally Posted by michaelpeg
As a general rule I'm with Headshake, I shoot for 78f +/- 2 degrees. A little less then that not to worry, more then that I start looking for more CO2.
Last edited by oldmac; Jul-25-2009 at 23:50.
Keep it civil please, gentlemen. -StinkyAttic