I usually like 20-24" before going 12/12 depending on the variety remember more branches more yield ...
ledhed said:That also depends on your growspace. In my flowering cabinet I want 'em to TOP OUT at around 24", so if I start flowering with plants taller than 8 or 10 inches, I got troubles.
For me, that means to grow them to sexual maturity, I have to keep topping them. The GOOD news is that topping means more branches, and as Big sez, more branches = more buds.
Now clones are different. They come out sexually mature (sounds kinda dirty, don't it?) so you just veg them until they're as big as you want.
Griff, If you are talking about the seeds you germed last week, you're probably looking at around June 1st or later before you flip them.