Good time to take clones.

I am about 3 weeks into this grow from seed. I am wondering when is a good time to take clones?

Bump bump bump

How big are the plants and how many growth points? if youve got cloneable bottom branches and want to do it now, knock yourself out . lol.since im a nice guy I'm going to let you in on something alot of people dont realize/misunderstand, Youve probally seen people saying that cloning from vegging plants is superior to cloning from flowering plants, that is a total myth. Flowering clones are better imo., i'll find you the link that opened my eyes to this......(im not saying not to take any veg clones, just that later on when your further along you should try flowering clones out.)

here, check it out my friend, http://www.420magazine.com/forums/seeds-clones-strains/56864-what-flowering-clone.html

Thanks that good information.

Question, how warm usually does my bubble cloner need to be in order to get the best chances of a successful rooting? is 72f to cold still?